CN111987180A

CN111987180A - Solar power generation window based on selective ultraviolet absorption of colloidal silica quantum dot nanoparticles

Info

Publication number: CN111987180A
Application number: CN202010867042.0A
Authority: CN
Inventors: 寿春晖; 杜长庆; 金胜利; 彭浩; 韩杉杉; 贺海晏; 黄绵吉; 丁莞尔; 邬荣敏; 周剑武
Original assignee: Shanghai Jiaotong University; Zhejiang Energy Group Research Institute Co Ltd
Current assignee: Shanghai Jiaotong University; Zhejiang Energy Group Research Institute Co Ltd
Priority date: 2020-08-26
Filing date: 2020-08-26
Publication date: 2020-11-24

Abstract

The invention relates to a solar power generation window based on selective absorption of ultraviolet rays by colloidal silicon quantum dot nanoparticles, which comprises: SiQDNPs-LSC (silicon quantum dot nano particle solar concentrator), power generation window and reflector; and a silicon-based photovoltaic cell strip (Si PV strip) is arranged in the power generation window, and the upper surface of the silicon-based photovoltaic cell strip is adhered to the lower surface of the SiQDNPs-LSC. The invention has the beneficial effects that: under simulated sunlight, since SiQDNPs absorb mainly only ultraviolet rays, the propagating red fluorescence is hardly reabsorbed, while sunlight passing through the glazing retains extremely high AVT and CRI; the SiQDNPs-LSC can generate higher power conversion efficiency, wherein the fluorescence contribution of the SiQDNPs accounts for a large proportion, and meanwhile, the SiQDNPs-LSC retains higher spectral quality and is beneficial to window application.

Description

Solar power generation window based on selective ultraviolet absorption of colloidal silica quantum dot nanoparticles

Technical Field

The invention belongs to the technical field of integrated photovoltaic Building (BIPV), and particularly relates to a solar power generation window capable of selectively absorbing ultraviolet rays based on colloidal silicon quantum dot nanoparticles.

Background

The solar power generation window changes a common skylight or a vertical window into a small-sized generator so as to expand a power grid and play an indispensable role in an integrated photovoltaic Building (BIPV). BIPV is an emerging renewable energy technology that can replace or retrofit conventional building components with photovoltaic components. Especially for high-rise buildings in highly urbanized areas, the space for installing ground or roof solar panels is far from sufficient to compensate for the energy consumption of the building itself. Therefore, in order to achieve the ultimate goal of near-zero energy consumption buildings actively pursued by many countries, energy harvesting using the huge window area of high-rise buildings is an effective method.

Although the efficiency of the solar power generation window is not as good as that of the traditional solar panel, the solar power generation window can still generate enough electric quantity when being connected to a large power utilization network. Meanwhile, the solar power generation window must meet certain safety requirements and keep semitransparent so that building residents can enjoy natural light. Ideally, a solar power window would absorb and collect only the Ultraviolet (UV) and Near Infrared (NIR) portions of the solar spectrum, altering the incident spectrum through the visible portion (similar to a low-emissivity coating on a window) to improve the energy efficiency of the building.

Several transparent photovoltaic Technologies have emerged in Solar power window applications, some of which have been commercialized by companies (e.g., Onyx Solar, Ubiquitous Energy, SolarWindow Technologies, and UbiQD) and installed on globally famous buildings. Silicon thin film technologies, in which space segmentation or intermediate colors are of greatest interest in the solar power window market. Furthermore, semi-transparent thin films (dye-based and dye-sensitized photovoltaic cells) based on organic and organic-inorganic hybrid materials (e.g. perovskites) have recently received attention, but long-term stability of semi-transparent thin films must be improved before widespread deployment can be achieved. These thin film devices, while capable of high Power Conversion Efficiencies (PCEs) as high as 14%, have broad absorption capabilities for the solar spectrum, including the visible range, resulting in relatively low average visible light transmission (AVT).

On the other hand, visible transparent Luminescent Solar Concentrators (LSCs) with selective absorption of UV and/or NIR wavelengths can easily achieve AVTs higher than 50%, a crucial property for applications with visible light transmittance. Furthermore, LSCs (typically waveguide plastic or glass panels coated or embedded with fluorophores) with simple structures can seamlessly replace or retrofit existing windows without degrading their original aesthetic qualities. Under sunlight, the fluorophore fluoresces and is then guided by the LSC, guided by total reflection towards the edges where conventional photovoltaic cells convert the fluorescence into electrical energy. The LSC sidewall area is much smaller than the photovoltaic cell. At the front surface, the flux of fluorescent photons received by the photovoltaic cell is concentrated and the photovoltaic material cost is reduced.

LSC performance is evaluated from two important aspects, namely conversion efficiency (e.g., PCE and optical efficiency) and spectral quality (e.g., AVT and color rendering index, CRI), which are typically inversely proportional to each other. To achieve high conversion efficiency without sacrificing spectral quality, fluorophores used in LSCs need not only have high photoluminescence quantum efficiency (PLQY), but must also be capable of selective absorption outside the visible and possess large stokes shifts to mitigate reabsorption effects, which is typically the major loss of fluorescence conduction on LSCs. For a single junction with 100% AVT, the thermodynamic limit of PCE for LSC of UV and NIR selectivity may be as high as 21%. Recently, various fluorophores with the above-mentioned optical properties have been explored to achieve efficient and visible LSCs for solar power generation window applications, including organic dyes, phosphorescent nanocrystals, sustainable natural organic molecules, carbon nanodots, perovskite quantum dots, and other heavy metal-free quantum dots.

In summary, a solar power generation window based on selective absorption of ultraviolet rays by colloidal silicon quantum dot nanoparticles is provided.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a solar power generation window based on the selective absorption of ultraviolet rays by colloidal silicon quantum dot nano particles.

The solar power generation window based on the selective ultraviolet absorption of the colloidal silicon quantum dot nano particles comprises: SiQDNPs-LSC (silicon quantum dot nano particle solar concentrator), power generation window and reflector; silicon-based photovoltaic cell strips (Si PV strips) are arranged in the power generation window, the upper surfaces of the silicon-based photovoltaic cell strips are adhered to the lower surfaces of the SiQDNPs-LSCs, and four peripheral edges of the SiQDNPs-LSCs are connected with the reflecting mirrors through epoxy resin;

the SiQDNPs-LSC comprises a front glass plate, a PMMA ring, a rear glass plate and a liquid SiQDNPs suspension thin layer (window glass); the lower surface of the front glass plate is attached to the upper surface of the PMMA ring, the upper surface of the rear glass plate is attached to the lower surface of the PMMA ring, and a gap structure is formed among the front glass plate, the PMMA ring and the rear glass plate; the thin layer of the liquid SiQDNPs suspension is a void structure of the SiQDNPs suspension filled in 1-octadecene; the back glass plate is the lower surface of the SiQDNPs-LSC.

Preferably, the mirror has an inclination of 45 ° in the horizontal direction of SiQDNPs-LSC.

Preferably, the mirror has an inclination of 0 ° in the horizontal direction of SiQDNPs-LSC.

Preferably, the front glass plate has a thickness of 0.1mm to 100 mm.

Preferably, the PMMA ring has a thickness of 0.1mm to 100 mm.

Preferably, the width of the silicon-based photovoltaic cell strip is 1 cm-10 cm.

The invention has the beneficial effects that:

(1) the invention designs that colloidal silicon quantum dot nano particles (SiQDNPs) are used as fluorescent materials of a Luminescent Solar Concentrator (LSC), and a silicon-based photovoltaic cell is provided with a front-coupled solar power generation window; the Luminescent Solar Concentrator (LSC) is composed of a liquid SiQDNPs suspension thin layer clamped between two thin glass plates, and the power generation window is manufactured by adhering the front surface of a silicon-based photovoltaic cell belt to the rear surface of the LSC; in order to prevent the fluorescence from leaking out of the edge, the four peripheral edges of the LSC are attached with reflecting mirrors;

(2) SiQDNPs dispersed in 1-octadecene are capable of selectively absorbing the ultraviolet portion of the solar spectrum and converting it to red fluorescence with high quantum efficiency; the fluorescence generated by SiQDNPs is finally directed to the forward silicon-based solar cell bands by the LSC intrinsic waveguide structure and the mirrors around the LSC edges, enhancing the overall PCE; since the overlap between the absorption spectrum and the photoluminescence spectrum of SiQDNPs is negligible, its loss due to reabsorption is insignificant; the preposed peripheral silicon photovoltaic strip not only can collect red fluorescence generated by SiQDNPs to generate electricity, but also can obtain direct solar radiation through forward design to generate electricity;

(3) under simulated sunlight, furthermore, since SiQDNPs primarily absorb only ultraviolet light, the propagating red fluorescence is hardly reabsorbed, while sunlight passing through the glazing retains extremely high AVT and CRI; the SiQDNPs-LSC can generate higher power conversion efficiency, wherein the fluorescence contribution of the SiQDNPs accounts for a large proportion, and meanwhile, the SiQDNPs-LSC retains higher spectral quality and is beneficial to window application.

Drawings

FIG. 1 is a 3D enlarged view of SiQDNPs-LSC (mirrors not shown);

FIG. 2 is a cross-sectional view of the edges of SiQDNPs-LSC;

FIG. 3 is a rear view of SiQDNPs-LSC;

FIG. 4 is a PCE gain plot for different sizes of SiQDNPs-LSC with the mirror tilted 45 and 0, respectively, under UV irradiation;

FIG. 5(A) is a schematic diagram of an experimental setup, and FIG. 5(B) is a measured PL spectrum for two slit positions;

FIGS. 6(A) and 6(B) are SiQDNPs-LSC (W) with the mirror tilted at 45 DEG and 0 DEG, respectively_LSC10cm) as a function of illumination wavelength (365nm, 465nm, 525nm, and 625 nm); FIGS. 6C and 6D show SiQDNPs-LSC (W) with the mirror tilted at 45 DEG and 0 DEG, respectively_LSC10cm) of overall PCE versus illumination wavelength;

FIG. 7(A) is a graph of PCE gain versus SiQDNPs concentration for SiQDNPs-LSC in simulated sunlight; FIG. 7(B) is an AVT or overall AVT diagram of the overall PCE and windowpane corresponding to (A); FIG. 7(C) 2.7 mg/mL^-1SiQDNPs-LSC (W)_LSC10cm) state diagram in an outdoor environment; FIG. 7(D) is a plot of CRI and CCT of SiQDNPs-LSC at different concentrations of SiQDNPs;

FIG. 8(A) is a schematic diagram of SiQDNPs-LSC installation; FIG. 8(B) is a photograph of SiQDNPs-LSC of different sizes with the mirror tilted at 45 ° (upper row) and tilted at 0 ° (lower row)

FIG. 9(A) is a spectrum of transmitted light of SiQDNPs-LSC glazing with and without SiQDNPs; FIG. 9(B) is a transmitted light spectrum at the SiQDNPs-LSC power generation window; FIG. 9(C) is a transmission spectrum of 5mm glass/2 mm 1-octadecene/5 mm glass.

FIG. 10 is a diagram of the optical path for critical cone analysis of the windowpane region of SiQDNPs-LSC;

FIG. 11(A) is a transmission spectrum through the region of the glazing of SiQDNPs-LSC, and FIG. 11(B) is an AM 1.5G photon flux plot; fig. 11(C) is an AM 1.5G spectral irradiance plot.

Description of reference numerals: the solar photovoltaic cell comprises a front glass plate 1, a PMMA ring 2, a rear glass plate 3, a silicon-based photovoltaic cell belt 4, a liquid SiQDNPs suspension thin layer 5, epoxy resin 6, a reflector 7, SiQDNPs suspension in 1-octadecene 8, fibers 9, a photomultiplier 10 and black paperboard 11.

Detailed Description

The present invention will be further described with reference to the following examples. The following examples are set forth merely to aid in the understanding of the invention. It should be noted that, for a person skilled in the art, several modifications can be made to the invention without departing from the principle of the invention, and these modifications and modifications also fall within the protection scope of the claims of the present invention.

Example 1:

as shown in fig. 1, the solar power generation window based on the selective absorption of ultraviolet rays by the colloidal silicon quantum dot nanoparticles includes: SiQDNPs-LSC, power generation windows and reflections; SiQDNPs-LSC comprises a front glass plate 1 (thickness 1 mm), a PMMA ring 2 (thickness 2 mm) and a rear glass plate 3 (thickness 1 mm); the gap structure formed by the two glass plates (front glass plate 1 and rear glass plate 3) and the PMMA ring 2 is filled with SiQDNPs suspension liquid; central square region (area W) containing suspensions of SiQDNPs_LSC×W_LSC) A thin layer 5 of a suspension of SiQDNPs in liquid state, while silicon photovoltaic strips (Si PV strips) (width 1cm) adhered to the back of SiQDNPs-LSC form the power generation window;

as shown in fig. 2, the edge of SiQDNPs-LSC is provided with a mirror 7 with bottom inclined upward by 45 ° or a mirror 7 with 0 ° (not inclined), and the mirror 7 with bottom inclined upward by 45 ° is connected with the front glass plate 1, the PMMA ring 2 and the rear glass plate 3 by epoxy resin 6; under 365nm ultraviolet irradiation, SiQDNPs-LSC with mirror 7 tilted at 45 ° showed more red fluorescence reflected along the power generation window, while SiQDNPs-LSC with mirror 7 tilted at 0 ° showed more red fluorescence escaping from the window glass.

Under illumination, front-mounted silicon-based solar cells (Si PV) can generate electricity by collecting light incident on the power generation window. At the same time, the fluorescence generated by the silicon quantum dots in the window glass can also be transmitted to the silicon-based photovoltaic cell strip 4, and the efficiency thereof is improved. The enhancement of efficiency can be quantified by the PCE gain, defined as the PCE of the silicon-based photovoltaic cell strip 4 measured with a suspension of SiQDNPs contained in a thin layer 5 of a suspension of SiQDNPs in liquid form, divided by the PCE measured with pure 1-octadecene in a glazing. To avoid the complexity of the wiring, we use for each SiQDNPs-LSCA ribbon of silicon-based photovoltaic cells 4 cut in small pieces from a conventional single crystal silicon solar cell wafer (PCE ═ 20.8%) is placed along only one SiQDNPs-LSC edge. The total light absorption area of the total PCE is calculated to be equal to (W)_LSC+2cm)×(W_LSC+2cm) and the total electrical energy generated is equal to the total electrical energy generated by one ribbon 4 of silicon-based photovoltaic cells multiplied by four.

Example 2:

to understand how the size of the glazing affects the reinforcing effect, different W's under 365nm UV irradiation were investigated_LSCPCE gain at size (fig. 4 and table 1). In FIG. 4, the UV intensity is equal to 0.97mW cm^-2The wavelength was 365nm and the concentration of the suspension of SiQDNPs was about 0.7 mg/mL^-1. Table 1 below shows SiQDNPs-LSC (W) of various sizes under 365nm UV illumination_LSC2cm, 4cm, 6cm, 8cm and 10cm) short-circuit current (I)_SC) Open circuit voltage (V)_OC) Fill Factor (FF) and maximum power value.

TABLE 1 SiQDNPs-LSC parameter value table for different sizes under UV illumination

Since the intensity of light incident on the surface of SiQDNPs-LSC is constant (0.97mW cm)^-2) Thus, a suspension of SiQDNPs (about 0.7mg mL) loaded in a glazing^-1) The maximum power obtained versus the ratio obtained using pure 1-octadecene in the glazing (i.e., without SiQDNPs) corresponds to the PCE gain shown in fig. 4. I highlighted when the mirrors are respectively tilted by 45 ° and respectively tilted by 0 °_SCThe difference therebetween is Δ I_SCFor calculating W_LSCEta of SiQDNPs-LSC of 10cm and mirror tilt of 45 °_opt. Two groups I_SCThe difference between them is Δ I_SCFor calculating W_LSCEta of SiQDNPs-LSC of 10cm and mirror tilt 0 °_opt。

Curve #1 in FIG. 9(A) shows the light path through 1mm glass/2 mm 1-octadecene/1 mm glass; curve #2 shows a suspension of 1mm glass/2 mm SiQDNPs (approx0.7mg mL _ 1)/1mm glass optical path; curve #3, which is the absorption of SiQDNPs dispersed in 1-octadecene, is curve #1 minus curve # 2; at 365nm, the absorption was 50%; the curve in FIG. 9(B) represents the optical path of 1mm glass/2 mm PMMA/1mm glass, and is almost the same as the curve #1 in FIG. 9 (A). In fig. 10, path (a) represents the critical cone loss and path (C) represents total internal reflection; the light path (B) shows that the incident angle of the fluorescent light beam at the glass-air interface is equal to theta_C(critical angle) and the angle of incidence at the 1-octadecene-glass interface is equal to θ₁The situation of time; at this time, according to Snell's law, 1.44 × sin θ₁＝1.46×sinθ _C1 × sin 90 ° -1; the percentage of fluorescence photons within the glazing that can propagate by total internal reflection to the LSC edge, i.e.. eta_optIs equal to (1-1/1.44)²)^1/2＝72％。

During the experiment, for each W_LSCPCEs with and without SiQDNPs were measured using the same SiQDNPs-LSC but with different contents in the glazing. In general, a larger light absorption area results in more fluorescence generated inside the glazing, thus increasing the PCE of the silicon-based photovoltaic cell strip 4. In particular, in W_LSCIn the case of 10cm, the PCE gain can be as high as 2.24 and 1.28 when the mirrors are tilted by 45 ° and 0 °, respectively. However, when W_LSCWhen the PCE drops below 2cm, the PCE is nearly uniform. Further, optical efficiency (. eta.)_opt) Defined herein as the percentage of fluorescence photons generated inside the glazing that are able to propagate to and be received by the Si PV, can be calculated using the following formula:

wherein Δ I_SCShows the short-circuit current difference of one silicon photovoltaic strip measured with and without SiQDNPs (table 1), I_lightThe intensity of incident light at 365nm (═ 0.97mW cm)^-2)，A_SiQDNPsThe absorbance of the SiQDNPs layer at 365nm (═ 50%, fig. 9(a)), h ν_365nmIs a photon energy of 365nm (═ 5.44X 10^- ¹⁹J)，

Is PLQY (about 0.35) and at 365nm of the SiQDNPs layer

Quantum efficiency of Si PV at 650nm (about 0.95).

For W_LSCSiQDNPs-LSC, eta, 10cm and mirror tilt 45 °_optEstimated to be 49%, and η defined by Snell's law_optThe maximum theoretical value of (c) is 72%. In other words, except for 28% escape cone loss, about 32% of the propagating fluorescence photons are lost when propagating through the waveguide by total internal reflection, and eventually absorbed by the Si PV. Reasons for the loss of the propagating fluorescence photons may include: (1) reabsorption of SiQDNPs, (2) absorption by the glass slab, (3) scattering due to imperfect waveguide structures and (4) non-ideal reflectivity of the mirror. For comparison, for the same W_LSCSiQDNPs-LSC, η of size (═ 10cm) but with mirror tilt 0 °_optEstimated to be 28%, which is much lower than using W_LSCEta obtained_opt(═ 49%). The mirrors are tilted by 45 deg. because most of the fluorescence photons propagating perpendicular to the edge will be reflected back into the waveguide by the perpendicular mirrors, resulting in a higher probability of the loss mechanism being depleted. As shown in fig. 3, the stronger red fluorescence escaping from the window glass is a manifestation.

To find out the key factor in the loss of fluorescence photons as they propagate in the region of the glazing, we characterized the fluorescence (PL) collected from the edge of SiQDNPs-LSC when only one of the glazing slits was exposed to 365nm uv radiation (fig. 5), a device in which SiQDNPs-LSC (no mirror) and only one of the glazing slits was exposed to 365nm uv radiation. FIG. 5(A) shows the optical setup for measuring the edge fluorescence spectra of SiQDNPs-LSC at two different slit positions, in FIG. 5(A), the #1 device and the #2 device both use a fiber 9 and a photomultiplier 10, the fiber 9 is connected to a beam splitter, and the beam splitter is connected to the photomultiplier 10; FIG. 5(B)) The method comprises the following steps: the PL spectrum measured with the slit arrangement #1 curve showed a 6nm blue shift of the PL peak and a reduction in the integrated area of about 30% compared to the slit arrangement #1 curve. Wherein the 365nm ultraviolet light intensity incident on the surface of the SiQDNPs-LSC is 4mW cm^-2The concentration of SiQDNPs was about 0.7 mg/mL^-1. PL spectra were obtained using multimode silica fiber (numerical aperture 0.22) with one end fixed to the edge of SiQDNPs-LSC and the other end connected to a fluorescence spectrophotometer consisting of a monochromator and photomultiplier tube (PMT). The relative position between the multimode silica fiber and the edges of the SiQDNPs-LSC is always kept constant and the small gap between the two parts is filled with immersion lens oil (refractive index 1.52) to promote the entry of fluorescence into the fiber. At a slit distance of 9cm from the silicon-based photovoltaic cell ribbon (# 2 device in fig. 5), the fluorescence spectrum shows a 6nm blue-shift of the PL peak compared to the spectrum obtained with the slit next to the silicon-based photovoltaic cell ribbon (# 1 device in fig. 5). This blue shift is due to the absorption of soda lime glass, which has a stronger absorption in the red spectral range (fig. 9 (C)). Although both front and rear glass plates are thin (1 mm), the cumulative thickness of the beam through the glass may be large, taking into account the fact that multiple total internal reflections may be required for the red fluorescent beam to reach the LSC edge. Unlike most other LSCs, reabsorption due to fluorophores is less pronounced here relative to glass absorption, since SiQDNPs reabsorption should result in a red-shift of PL rather than a blue-shift based on absorption spectra. (FIG. 5(B)) furthermore, the fluorescence reabsorption effect is insignificant since the overlap between absorbance and PL spectra of SiQDNPs suspensions is negligible and has a small molar extinction coefficient at wavelengths greater than 500 nm. Finally, the integrated area of the PL spectrum measured by slit #2 is 30% smaller than the integrated spectrum measured by slit #1, indicating that about 30% of the fluorescence photons are lost when propagating within a distance of 9 cm. A window glass. In practice, the average propagation distance of the fluorescence photons should be less than 9cm in a 10cm x 10cm glazing. The window glass loss analysis here is consistent with the previously estimated optical efficiency (η) taking into account other potential losses at the LSC edge_opt49%, i.e. about 32% of the propagating fluorescence photons are lost before being received by the Si PV) W_LSC＝10SiQDNPs-LSC of cm and mirror tilt of 45 deg..

Next, SiQDNPs-LSC (W) were characterized under 365, 465, 525 and 625nm single wavelength illumination_LSC10cm) and overall PCE (table 2). The single wavelength light sources in FIGS. 6(A) and 6(B) use 365nm, 465nm, 525nm and 625nm high power LEDs, and the light intensity incident on the surface of the SiQDNPs-LSC is equal to 0.97mW cm^-2、0.93mW*cm^-2、1.00mW*cm^-2And 0.84mW cm^-2. Wherein the concentration of SiQDNPs is about 0.7 mg/mL^-1. The curves in the figure represent the absorption of SiQDNPs in a glazing. The illumination wavelengths in fig. 6(C) and 6(D) include 365nm, 465nm, 525nm and 625nm, and the upper curves in fig. 6(C) and 6(D) represent the overall PCE of LSC measurements filled with SiQDNPs, and the lower curves represent the overall PCE of LSC measurements not filled with SiQDNPs. Table 2 below shows SiQDNPs-LSC (W) under 365nm, 465nm, 525nm and 625nm single-wavelength light source irradiation_LSC10cm) short-circuit current (I)_SC) Open circuit voltage (V)_OC) Fill Factor (FF) and PCE value; the single wavelength light source is generated by 365nm, 465nm, 525nm and 625nm high-power light emitting diodes, and the light intensity incident on the surface of the SiQDNPs-LSC is respectively equal to 0.97mW cm^-2、0.93mW*cm^-2、1.00mW*cm^-2And 0.84mW cm^-2. The concentration of SiQDNPs was about 0.7 mg/mL^-1. The total PCE is calculated using a total light absorption area equal to 12cm x 12cm and the total electrical energy generated is equal to the total electrical energy generated by one silicon photovoltaic strip shown in the table multiplied by four.

TABLE 2 parameter value table of SiQDNPs-LSC under different wavelength light source irradiation

In general, SiQDNPs-LSC with mirrors tilted at 45 ° have higher optical efficiency (η) than mirrors tilted at 0 °_opt49% versus 28%), thus showing a higher PCE gain, but an overall relatively lower PCE, because the Si PV is partially obscured by the 45 ° tilted mirror (fig. 2). In addition to this, the present invention is,the trend of PCE gain is nearly consistent with the trend of absorption of SiQDNPs (# 3 curves in fig. 1, 2, and 9), indicating that the gain should be due to fluorescence generated by SiQDNPs. SiQDNPs-LSC with mirrors tilted 45 and 0, respectively, have high PCE gains of 2.24 and 1.28, respectively, under 365nm illumination. However, since SiQDNPs are in>The absorption at the wavelength of 500nm is negligible and thus the PCE gain values in the green and red spectral ranges are nearly equal, tending to be uniform. On the other hand, the overall PCE trend of LSCs without SiQDNPs added in the glazing (lower curves in fig. 6(C) and 6(D), respectively) correlates with the transmission spectrum through the ribbon region of the silicon-based photovoltaic cell (fig. 9 (B)). The overall PCE measured with SiQDNPs in the glazing (upper curves in fig. 6(C) and 6(D), respectively) is higher than the PCE measured without SiQDNPs due to fluorescence enhancement at 365 and 465nm illumination. Under 525nm illumination, the PCE gain is negligible for SiQDNPs-LSCs with mirrors tilted 45 ° and 0 °, respectively, and the overall PCE reaches a maximum of 1.3% and 2%, respectively. While the overall PCE decreases at 625nm, which may be due to the stronger absorption of the soda-lime glass slab in the red spectral range.

In addition to wavelength-resolved analysis, we also analyzed SiQDNPs-LSC (W) for the concentrations of different SiQDNPs suspensions (fig. 7(a) and 7(B) and table 3)_LSC10cm) PCE gain and overall PCE under simulated sunlight were characterized. W in FIG. 7(A)_LSCThe concentration of SiQDNPs was 0.9 mg/mL at 10cm^-1、1.8mg*mL^-1、2.7mg*mL^-1And 3.6 mg/mL^-1These four values; the simulated sunlight was generated by a conventional xenon lamp with a light intensity of 6.51mW cm incident on the surface of SiQDNPs-LSC^-2. In fig. 7(B), for SiQDNPs-LSC in the case of fig. 7(a), AVT or overall AVT (═ windowpane AVT) × 10 of the overall PCE and windowpane is calculated²/12²) For each data point, the corresponding concentrations of SiQDNPs are labeled. Table 3 below shows SiQDNPs-LSC (W) at different concentrations of SiQDNPs in simulated sunlight_LSC10cm) short-circuit current (I)_SC) Open circuit voltage (V)_OC) Fill Factor (FF) and PCE value. Here, the simulated sunlight is generated by a conventional xenon lamp and is incident on the SiQDNPs-LSC tableThe light intensity of the surface was 6.51mW cm^-2. Note that the total PCE is calculated using a total light absorption area equal to 12cm x 12cm and the total power generated is equal to the total power generated by one silicon photovoltaic strip shown in the table multiplied by four.

TABLE 3 parameter value table of SiQDNPs-LSC simulating different SiQDNPs concentrations in sunlight

In fig. 8(a), the size of the strip-shaped silicon photovoltaic panel 4 is 13cm × 1cm, and the silicon photovoltaic panel 4 covers exactly one fourth of the whole power generation window area; each SiQDNPs-LSC in fig. 8(B) is coupled to 4 strips of one silicon photovoltaic panel. The width (1cm) of the power generation window is kept constant, while the window glass area (W)_LSC×W_LSC) Different. A small hole is opened on the PMMA ring for injecting or extracting SiQDNPs suspension or pure 1-octadecene.

Similar to the single wavelength experiments described above, SiQDNPs-LSC tilted at 45 ° showed higher PCE gain compared to mirror tilt at 0 °, but the overall PCE was relatively low. Furthermore, as more fluorescence is generated within the glazing, the PCE gain, and hence the overall PCE, increases as the concentration of SiQDNPs increases. However, when the concentration of SiQDNPs becomes too high, the absorption of SiQDNPs (especially in the UV range) saturates (fig. 11(a)), i.e., further increase in the concentration of SiQDNPs does not result in more fluorescence being generated. On the other hand, reabsorption losses increase due to high SiQDNPs concentrations. Thus, the PCE gain and total PCE value of SiQDNPs-LSC with mirrors tilted at 45 ° and 0 ° were at a high concentration of 3.6mg mL^-1All the concentrations are lower than the low concentration of 2.7mg mL^-1. FIG. 11(A) Transmission Spectrum T (λ) through the region of the glazing of SiQDNPs-LSC filled with pure 1-octadecene (curve a), 0.9mg × mL^-1(curve b), 1.8 mg/mL^-1(c Curve) and 3.6 mg/mL^-1Suspensions of SiQDNPs (curve d). As the concentration of SiQDNPs increases, the absorption of SiQDNPs tends to saturate, particularly in the UV range. Further, comparison is made with the brightness function P (λ) (black dashed line). FIG. 11(B) AM 1.5G photon flux settingIs S_flux(lambda). FIG. 11(C) AM 1.5G spectral irradiance set to S_irradiance(lambda). The AVT is calculated as follows: integral multiple of T (lambda) P (lambda) S_flux(λ)dλ/∫P(λ)S_flux(λ) d λ. The CRI and CCT values are estimated based on: t (lambda) S_irradiance(λ)。

In terms of spectral properties, since the suspensions of SiQDNPs absorb mostly in the UV range and hardly in the visible range, the AVT and CRI measured in the region of the glazing exceed 80% and 90%, respectively, and the Correlated Color Temperature (CCT) is typically higher than 4000K (fig. 7(B) and 7(C)), respectively. Furthermore, since silicon-based photovoltaic cell ribbons composed of Si PV strips (width 1cm) are completely opaque, they can be produced by multiplying the window glass AVT by 10²/12²To calculate the total AVT. In summary, when the concentration of SiQDNPs is equal to 2.7mg mL^-1The PCE gain for SiQDNPs-LSC with mirror tilt of 45 ° and 0 ° is 1.06 and 1.02, respectively, with an overall PCE of 2.47% and 4.37%, respectively. The AVT of the glazing is 86%, the overall AVT is 60%, the CRI is 94, and the CCT is 4612K. Compared to other solar power window technologies, such as large capacity heterojunction organic photovoltaic cells (PCE 4%, AVT 64.4%, CRI 94.5), near infrared selective exciton semiconductor photovoltaic cells based on organic salt derivatives (PCE 5.1%, AVT 51.5% and CRI 65.3) and NIR selective LSCs (PCE 0.4%, AVT 88.3% and CRI 94.3), SiQDNPs-LSC obtain similar PCEs in this work, while obtaining excellent spectral characteristics due to UV selective absorption of SiQDNPs. By using a larger W_LSCWhile keeping the width of the Si PV strip the same, the PCE gain (following the trend shown in FIG. 4) and the overall AVT (i.e., windowpane AVT multiplied by a factor W)_LSC ²/(W_LSC+2)²This can be further improved.

And (4) conclusion:

the novel solar power generation window structure provided by the invention combines the concepts of space segmentation PV and LSC; the glazing consists of a suspended thin layer of SiQDNP sandwiched between two thin glass sheets, while a Si PV strip placed forward along the perimeter of the LSC forms the power generation window; in sunlight, a forward placed silicon photovoltaic panel (Si PV) not only directly collects solar radiation, but also utilizes the fluorescence generated by SiQDNP conducted from the window glass.

SiQDNP (by hydrosilylation)<10nm) with 1-octene to form a homogeneous and stable suspension in 1-octene. The selective molar extinction coefficient of the SiQDNP suspension at 350nm UV light is equal to 2.68X 10⁵M^-1cm^-1And re-emitted red fluorescence (peak at about 650nm) at a PLQY value of 42%. PCE gain vs. windowpane size (W) for SiQDNP-LSC in general_LSC) And SiQDNP absorption. PCE gain (W) of SiQDNP-LSC under 365nm ultraviolet irradiation_LSC10cm, SiQDNP concentration 0.7mg mL^-1The mirror tilt 45 deg. can be as high as 2.24, which corresponds to an optical efficiency (η)_opt) Equal to 49%. In contrast, Snell's law defines the maximum theoretical η_optThe content was 72%. Here, the main optical loss is due to absorption by the soda lime glass slab rather than SiQDNP reabsorption. Finally, under simulated sunlight, SiQDNP-LSC (W)_LSC10cm, SiQDNP concentration 2.7mg mL^-1The total PCE for a mirror tilt of 45 °) is 2.47%, the PCE gain is 1.06, the windowpane AVT is 86%, the total AVT is 60%, the CRI is 94, and the CCT is 4612K.

The SiQDNP-LSC in this work achieved a similar PCE compared to other solar window technologies, while achieving excellent spectral characteristics due to the uv selective absorption of SiQDNP.

Claims

1. Solar power generation window based on ultraviolet is absorbed to colloidal silica quantum dot nano particle selectivity, its characterized in that includes: SiQDNPs-LSC, power generation windows and reflectors; a silicon-based photovoltaic cell belt (4) is arranged in the power generation window, the upper surface of the silicon-based photovoltaic cell belt (4) is adhered to the lower surface of the SiQDNPs-LSC, and four peripheral edges of the SiQDNPs-LSC are connected with a reflector (7) through epoxy resin (6);

the SiQDNPs-LSC comprises a front glass plate (1), a PMMA ring (2), a rear glass plate (3) and a liquid SiQDNPs suspension thin layer (5); the lower surface of the front glass plate (1) is attached to the upper surface of the PMMA ring (2), the upper surface of the rear glass plate (3) is attached to the lower surface of the PMMA ring (2), and a gap structure is formed among the front glass plate (1), the PMMA ring (2) and the rear glass plate (3); the liquid SiQDNPs suspension thin layer (5) is a void structure filled with SiQDNPs suspension (8) in 1-octadecene; the rear glass plate (3) is the lower surface of the SiQDNPs-LSC.

2. The solar power generation window based on selective absorption of ultraviolet by colloidal silicon quantum dot nanoparticles as claimed in claim 1, wherein: the inclination angle of the reflecting mirror (7) in the horizontal direction of SiQDNPs-LSC is 45 degrees.

3. The solar power generation window based on selective absorption of ultraviolet by colloidal silicon quantum dot nanoparticles as claimed in claim 1, wherein: the inclination angle of the reflecting mirror (7) in the horizontal direction of SiQDNPs-LSC is 0 degree.

4. The solar power generation window based on selective absorption of ultraviolet by colloidal silicon quantum dot nanoparticles as claimed in claim 1, wherein: the thickness of the front glass plate (1) is 0.1 mm-100 mm.

5. The solar power generation window based on selective absorption of ultraviolet by colloidal silicon quantum dot nanoparticles as claimed in claim 1, wherein: the thickness of the PMMA ring (2) is 0.1 mm-100 mm.

6. The solar power generation window based on selective absorption of ultraviolet by colloidal silicon quantum dot nanoparticles as claimed in claim 1, wherein: the width of the silicon-based photovoltaic cell strip (4) is 1 cm-10 cm.