tailieunhanh - Photoelectrical Characteristics of UV Organic Thin-film Transistor Detectors

In this paper, a pentacene photo organic thin-film transistor (photoOTFT) was fabricated and characterized. The gate dielectric acted as a sensing layer thanks to it strongly absorbs UV light. Electrical behaviors of photoOTFT were measured under 365 nm UV illumination from the gate electrode side. | VNU Journal of Science: Mathematics – Physics, Vol. 33, No. 2 (2017) 74-81 Photoelectrical Characteristics of UV Organic Thin-film Transistor Detectors Dao Thanh Toan* Faculty of Electrical-Electronic Engineering, University of Transport and Communications, , Cau Giay, Dong Da, Hanoi, Vietnam Received 16 March 2017 Revised 05 May 2017; Accepted 30 May 2017 Abstract: In this paper, a pentacene photo organic thin-film transistor (photoOTFT) was fabricated and characterized. The gate dielectric acted as a sensing layer thanks to it strongly absorbs UV light. Electrical behaviors of photoOTFT were measured under 365 nm UV illumination from the gate electrode side. The current in transistor channel was significantly enhanced by photoelectrons at interface of buffer/gate dielectric. Photosensitivity increased with the light intensity but decreased with the applied gate voltage. Meanwhile the photoresponsivity decreased with the light intensity and increased with the applied gate voltage. The transistor responses well with the pulse of light with many test cycles of light-on and light-off. The best photosensitivity, photoresponsivity, rising time and falling time parameters of the device were found to be about 104, A/W, and s, respectively. The obtained photoelectrical results suggest that the photoOTFT can be a good candidate for practical uses in low-cost UV optoelectronics. Keywords: Pentacene phototransistor, UV sensor, organic electronics, optoelectronics. 1. Introduction In recent years, electronic components manufacturing from organic materials have been intensively studied due to their modern applications of low-cost, flexible, large area, lightweight lighting, and bendable display, which are hard to be realized using conventional inorganic semiconductors [1 5]. Evidently, an OLED Television has been succeeded to enter in the market and the OLED technology is going to occupy in all displays of the modern electronic products. Besides OLED, .