Organic field effect transistor and applications in ultraviolet sensing

Abstract

The invention provides an organic field effect transistor which uses a compound shown in a formula I as described in the specifications as an organic semiconductor layer, and a manufacturing method thereof and applications thereof. In the formula I, R1 and R2 can be the same or different and selected from at least one of hydrogen, substituted or unsubstituted C1-C50 alkyl, and substituted or unsubstituted C6-C50 aryl, and X is C=C or C-C triple bond. The organic field effect transistor has excellent device stability, the sensing response difference for incident lights of different wavelengths is significant, an extremely sensitive sensing response to an UVA with the light intensity to be only 37muWcm<-2> and the wavelength to be 365 to 420nm, light responsibility (R) exceeds 6000A/W, photosensitivity (P) can maximally reach 6.75*105, and thus the organic field effect transistor can be used for manufacturing an ultraviolet sensor, photosensitivity of the manufactured ultraviolet sensor in UVA is basically not changed along with changes of the light intensity, and great advantages are provided in the aspect of incident light distribution region reverse detection.

Description

technical field [0001] The invention relates to the fields of organic field effect transistors and optical sensing, in particular to a class of organic semiconductor materials containing benzo[1,2-b:4,5-b']dithiophene dimers and organic semiconductor materials based on such materials. A field effect transistor, a preparation method of the organic field effect transistor and its application in ultraviolet light sensing. Background technique [0002] Organic field-effect transistors (OFETs) are active devices that utilize an electric field to regulate the conductivity of organic semiconductor materials. Over the years, organic field effect transistor materials and devices have been greatly developed due to their great advantages in large area, low cost, flexible preparation, and solution processing. In recent years, with the help of the physical and chemical properties of organic semiconductor materials and the sensitive detection ability of transistors for small currents, th...

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Problems solved by technology

[0003] The initial reports on phototransistors of organic conjugated small molecules did not attract widespread attention because the device performance of these phototransistors was much lower than that of inorganic phototransistors (R≥300A / W)

In 2008, Cho et al reported a phototransistor based on 4(HPBT)-benzene thin film (Adv.Funct.Mater.2008,18,2905-2912), for a wavelength of 436nm and an intensity of 6.8-30μW / cm 2 The visible light exhibits a photoresponsivity of 2500-4300A / W and a 10 4 photosensitivity, but the carrier mobility is only 0.0013cm 2 / (Vs)

In 2010, Guo et al. prepared a phototransistor based on Me-ABT single crystal (Adv. Funct. Mater. 2010, 20, 1019-1024). Due to the great reduction of defects and grain boundaries in the single crystal structure, the semiconductor material The solid-state stacking structure has been significantly improved, and the photoresponsivity, photosensitivity and carrier mobility of the device have reached 12000A / W, 6000 and 1.66cm 2 / (Vs), but in this report only the light intensity is 30μW / cm 2 The white light was tested

Most of the organic phototransistor materials and devices reported so far only use a single light source for photoresponse testing. Even if a high-sensitivity response performance is observed, there is no comparison of device performance (stable differential response) under irradiation with other wavelengths. Determining the Wavelength Selectivity of Materials

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