Ultra Thin Film Field Effect Transistor Sensor and Its Application

Abstract

The invention discloses an ultrathin film field effect transistor and an application thereof. A transistor sensor comprises a grid layer, an insulation layer, an organic sensing layer, a source and drain, and is in the following structure a (a bottom grid top contact type), or the following structure b (a bottom grid bottom contact type), wherein for the structure a, the insulation layer is located above the grid layer, the organic sensing layer is located above the insulation layer, and the source and the drain are located on the same layer and above the organic sensing layer. The organic sensing layer is made of a compound shown as Formula I as shown in the specification. The transistor sensor can make a quick and sensitive sensing response to ammonia at the room temperature, is high in selectivity, restorable, low in manufacturing cost and simple in technology, is one of the most sensitive ammonia sensors at present, facilitates device miniaturization and integration, and is suitable for larger scale production, and a limit of detection of the transistor sensor can reach 0.1ppm.

Description

technical field [0001] The invention relates to the field of organic semiconductor materials and gas detection sensors, in particular to an ultra-thin film field effect transistor sensor and its application. Background technique [0002] Ammonia (NH 3 ) as an important raw material for ammoniation, is widely used in the production of precursors of various chemical products such as nitric acid and urea, pesticides, medicines and fertilizers, and its liquid form (liquid ammonia) is not only an effective industrial refrigerant, It is also widely used in the manufacture of rockets and missile propellants in the fields of national defense and military industry. However, ammonia is a colorless, toxic, and flammable gas with a strong, pungent odour. Short-term exposure to low-concentration ammonia atmosphere can cause poisoning symptoms such as edema in the respiratory tract and gastric mucosa. In severe cases, it can produce neurotoxicity, cause tissue dissolution and necrosis, ...

AI Technical Summary

Problems solved by technology

[0005] In recent years, the research on the use of organic thin film transistor (OTFT) devices for gas sensing has attracted people's attention, and some people have used classic organic semiconductor materials, such as α-6-thiophene (α-6T), pentacene, phthalocyanine, etc. Derivatives, poly 3-hexylthiophene (P3HT), etc., are used in the sensing research of ammonia, but the device response or selectivity is not ideal

In 2012, the Katz research group of Johns Hopkins University in the United States used tris(pentafluorophenyl)borane as the signal receiving conversion layer to prepare ammonia sensors (Huang, W.; Besar, K.; LeCover, R.; Rule, A.M.; Breysse, P.N.; Katz, H.E., J.Am.Chem.Soc.2012, 134(36), 14650-14653.), the detection limit concentration reached 0.35ppm, but in the process of transistor device preparation, organic The semiconductor material layer needs copper phthalocyanine or cobalt phthalocyanine and tris(pentafluorophenyl)borane to be delicately co-evaporated with a thickness of 6nm under vacuum conditions, and the technical means are relatively strict.

Although this type of device shows good sensing characteristics, the uniformity between devices is poor due to the discontinuity of the film, which is not conducive to large-scale preparation and application.

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