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Fabrication of Flexible Image Sensor Based on Lateral NIPIN Phototransistors
Published on: June 23, 2018
Diffusion interface layer controlling the acceptor phase of bilayer near-infrared polymer phototransistors with
Tao Han1, Zejiang Wang2, Ning Shen2
1Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds Research and Application, School of Physics and Electronic Electrical Engineering, Xiangnan University, Chenzhou, 423000, People's Republic of China. than@xnu.edu.cn.
Abstract:
The narrow bandgap of near-infrared (NIR) polymers is a major barrier to improving the performance of NIR phototransistors. The existing technique for overcoming this barrier is to construct a bilayer device (channel layer/bulk heterojunction (BHJ) layer). However, acceptor phases of the BHJ dissolve into the channel layer and are randomly distributed by the spin-coating method, resulting in turn-on voltages (Vo) and off-state dark currents remaining at a high level. In this work, a diffusion interface layer is formed between the channel layer and BHJ layer after treating the film transfer method (FTM)-based NIR phototransistors with solvent vapor annealing (SVA). The newly formed diffusion interface layer makes it possible to control the acceptor phase distribution. The performance of the FTM-based device improves after SVA. Vo decreases from 26 V to zero, and the dark currents decrease by one order of magnitude. The photosensitivity (Iph/Idark) increases from 22 to 1.7 × 107.
