CN110646473A

CN110646473A - Preparation method of inorganic nanoparticle modified PVP insulating layer gas sensor

Info

Publication number: CN110646473A
Application number: CN201910922844.4A
Authority: CN
Inventors: 王丽娟; 孙强; 朱阳阳; 谢强; 王璐
Original assignee: Changchun University of Technology
Current assignee: Changchun University of Technology
Priority date: 2019-09-27
Filing date: 2019-09-27
Publication date: 2020-01-03

Abstract

The invention relates to a preparation method of an inorganic nanoparticle modified PVP insulating layer gas sensor. The sensor is an OFET device structure and comprises a silicon substrate (1), a silicon dioxide insulating layer (2), PVP/TiO₂The composite material insulating layer (3), the P3HT gas sensitive layer (4) and the Ag interdigital electrode (5) evaporated on the gas sensitive layer are prepared by the simple spin coating process of the device, and the Ag interdigital electrode (5) and TiO are evaporated by the vacuum evaporation technology₂The pyridine modification of the nano particles increases the compatibility with PVP polymer (6), and the pyridine modified TiO₂The nano particles (7) are mixed with PVP polymer to improve the dielectric constant of the insulating layer, so that the working voltage of the device is reduced, the power consumption of the device is reduced, the crystallization of the material P3HT of the gas sensitive layer is promoted, and the response capability of the sensor to gas is improved. The gas sensor has sensitivityHigh degree, working at room temperature and simple preparation process.

Description

Preparation method of inorganic nanoparticle modified PVP insulating layer gas sensor

Technical Field

The invention discloses a preparation method of an inorganic particle modified PVP insulating layer gas sensor, and relates to the field of gas sensors.

Background

With the continuous progress of modern society, a large amount of harmful gases such as nitrogen dioxide and formaldehyde are discharged into the atmosphere along with automobile exhaust and industrial production processes, so that the environment can be greatly damaged, and even if the harmful gases have extremely low concentration, the harmful gases can also cause irreversible damage to a human body, so that a novel device of a gas sensor is developed, the detection limit of the gas sensor is improved, and the device has important significance on environmental protection and human body health.

In recent years, Organic Field Effect Transistors (OFETs) have been developed at a high speed, however, most of the OFET sensors still have insufficient gas detection capability, and in order to solve the problems of accuracy and response capability of the gas detection sensors, researchers are continuously looking for new materials to construct OFET gas sensors with more excellent structures, wherein, the polymer materials are more and more concerned because of having foldable and bendable characteristics, but the polymer materials are used as insulating layers, because of lower dielectric constants, higher working voltages are required, energy loss and device temperature increase are caused, so that increasing the dielectric constant of the insulating layers is one of the research directions of the OFET devices, and the selection of excellent active layer materials is beneficial to improving the sensitivity to gas.

Disclosure of Invention

In order to solve the problems of the existing gas sensor, the invention provides a preparation method of an inorganic nanoparticle modified polyvinylpyrrolidone (PVP) insulating layer gas sensor, the performance of a device is optimized by preparing a composite insulating layer, and the method has the advantages of simple preparation process, low cost, high sensitivity of the prepared device and capability of working at room temperature.

The invention relates to a gas sensor device with an OFET structure, which comprises a silicon substrate (1), a silicon dioxide insulating layer (2) and PVP/TiO from bottom to top in sequence₂The device comprises a composite material insulating layer (3), a P3HT gas sensitive layer (4) and Ag interdigital electrodes (5) for detecting the performance change of the device.

The invention relates to a preparation method of an inorganic nanoparticle modified PVP insulating layer gas sensor, which comprises the following steps:

firstly, titanium dioxide (TiO)₂) Nanoparticles modified with pyridine to increase TiO₂Compatibility of nano particles and PVP polymer material, reduction of film roughness, reduction of leakage current, and preparation of TiO₂Dissolving the nano particles in toluene to obtain TiO₂Adding an ethanol solution with the same volume as the colloidal solution, centrifuging, adding the obtained white precipitate into pyridine, heating at 60-80 deg.C for reaction, centrifuging, and cleaning to obtain pyridine-modified TiO₂Nanoparticles (7).

Dissolving PVP polymer (6) in ethylene glycol solution, heating to 120-140 ℃, and then adding pyridine modified TiO₂Nano particles (7) react for 1-2 h, PVP polymer (6) and TiO modified by pyridine₂The mass ratio of the nano particles (7) is 1-3%.

The PVP/TiO obtained is then₂Dissolving the composite material in ethanol to prepare a solution with the concentration of 5-30 mg/ml, and carrying out PVP/TiO spin coating by using a simple spin coating method₂The composite material solution is rotated for 1-2 min at 2000-3000 rmp to form a film on cleaned silicon, and then the device is placed on an annealing device to be annealed at 140-160 ℃ for 2-3 h to form PVP/TiO₂A composite material insulating layer (3).

Spin-coating the P3HT solution dissolved in chlorobenzene and having a concentration of 5-30 mg/ml to the annealed PVP/TiO at 800-1000 rmp for 1-2 min₂Annealing at 100-120 ℃ for 20-30 min on the composite material insulating layer (3) to form a P3HT gas sensitive layer (4).

Finally 8 is multiplied by 10^-4And (3) evaporating 200-300 nm thick Ag interdigital electrodes (5) on the P3HT gas sensitive layer (4) by using a mask plate under the vacuum condition of Pa.

Drawings

FIG. 1 is a schematic structural diagram of an inorganic nanoparticle modified PVP insulating layer OFET gas sensor;

FIG. 2 PVP/TiO₂Schematic diagram of composite material insulating layer.

The method comprises the following specific implementation steps:

1. preparation of pyridine-modified inorganic nanoparticles

Mixing nanometer TiO₂The particles 10mg were dissolved in 50 ml of toluene solution to obtain TiO₂Adding ethanol with the same volume into the colloidal solution, uniformly mixing, centrifuging, putting the obtained white precipitate into pyridine, performing ultrasonic treatment while reacting at 60 ℃ for 3h, adding ethanol after the reaction is finished, centrifuging the mixture solution, and washing with deionized water twice to obtain inorganic nano particle TiO modified by pyridine₂。

2.PVP/TiO₂Preparation of composite materials

1g PVP polymer was dissolved in 60 ml ethylene glycol, the solution was heated to 140 ℃ and then pyridine modified 10mg TiO was added₂Reacting the nano particles for 2 hours, cooling to room temperature, centrifuging to obtain a precipitate, washing twice with deionized water to remove residual impurities to obtain PVP/TiO₂A composite material.

Preparation of OFET sensor

PVP/TiO prepared in the step 2₂The composite material is dissolved in ethanol to prepare PVP/TiO 20 mg/mL₂Cleaning silicon wafer with acetone, ethanol and distilled water, blowing dry with nitrogen, and adding PVP/TiO₂The composite material solution is rotated for 1 min under the condition of 2000 rmp to uniformly form a film on a silicon wafer, and then the silicon wafer is put into an annealing device to be annealed for 2h at 160 ℃ to prepare TiO₂Inorganic particle modified PVP insulating layer.

Dissolving a polymer semiconductor material P3HT in chlorobenzene to prepare a 10 mg/ml P3HT solution, spin-coating the P3HT solution for 20 s under the condition of 800 rmp, and annealing at 120 ℃ for 20 min to prepare a P3HT gas sensitive layer.

Finally, the vacuum degree is 8 multiplied by 10^-4And (3) evaporating 200 nm Ag interdigital electrodes on the P3HT gas sensitive layer by using a mask plate under the Pa condition.

Claims

1. A preparation method of an inorganic nanoparticle modified PVP insulating layer gas sensor is characterized by comprising the following steps: the device structure comprises a silicon substrate (1), a silicon dioxide insulating layer (2), PVP/TiO₂Composite material insulating layer (3), P3HT gas sensitive layer (4) and Ag fork for detecting device performance changeFinger electrode (5), PVP/TiO₂The composite material insulating layer (3) and the P3HT gas sensitive layer (4) are both prepared by a simple spin coating process, and the Ag interdigital electrode (5) is obtained by a vacuum evaporation technology.

2. The method for preparing the inorganic nanoparticle modified PVP insulating layer gas sensor according to claim 1, wherein: PVP/TiO₂The composite material insulating layer (3) is TiO₂Nanoparticle modified PVP Polymer (6) composites, and TiO₂The nanoparticles are pyridine modified to increase compatibility with PVP polymer (6), PVP polymer (6) and pyridine modified TiO₂The mass ratio of the nano particles (7) is 1-3%; PVP/TiO₂In the preparation process of the composite material insulating layer, PVP/TiO₂The composite material is dissolved in ethanol solvent, the concentration of the solution is 5-30 mg/ml, and PVP/TiO₂The composite material solution is spin-coated on a cleaned silicon wafer under the conditions of 2000-3000 rmp, the rotation is carried out for 1-2 min to form a film, and then the device is placed on an annealing device to be annealed for 2-3 h under the conditions of 140-160 ℃ to form PVP/TiO₂The composite material insulating layer (3) is a film.

3. The method for preparing the inorganic nanoparticle modified PVP insulating layer gas sensor according to claim 1, wherein: the P3HT gas sensitive layer (4) is made of PVP/TiO₂P3HT solution dissolved by chlorobenzene is spin-coated on the composite material insulating layer (5), the concentration of the solution is 5-30 mg/ml, and then annealing is carried out for 20-30 min under the conditions of 100-120 ℃.

4. The method for preparing the inorganic nanoparticle modified PVP insulating layer gas sensor according to claim 1, wherein: at 8X 10^-4And (3) evaporating an Ag interdigital electrode (5) on the P3HT gas sensitive layer (4) by using a mask plate under the vacuum condition of Pa for 200-300 nm.