Relieving the Photosensitivity of Organic Field-Effect Transistors

Jie Liu; Longfeng Jiang; Jia Shi; Chunlei Li; Yanjun Shi; Jiahui Tan; Haiyang Li; Hui Jiang; Yuanyuan Hu; Xinfeng Liu; Junsheng Yu; Zhongming Wei; Lang Jiang; Wenping Hu

doi:10.1002/adma.201906122

Relieving the Photosensitivity of Organic Field-Effect Transistors

Adv Mater. 2020 Jan;32(4):e1906122. doi: 10.1002/adma.201906122. Epub 2019 Nov 29.

Authors

Jie Liu¹, Longfeng Jiang², Jia Shi³, Chunlei Li¹, Yanjun Shi¹, Jiahui Tan⁴, Haiyang Li¹, Hui Jiang⁵, Yuanyuan Hu⁶, Xinfeng Liu³, Junsheng Yu², Zhongming Wei⁷, Lang Jiang¹, Wenping Hu⁸

Affiliations

¹ Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
² School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 610054, China.
³ Division of Nanophotonics, CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China.
⁴ Guangzhou China Ray Optoelectronic Materials Co., Ltd., Guangzhou, 510663, China.
⁵ School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
⁶ Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education and Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha, 410082, China.
⁷ State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China.
⁸ Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University, Tianjin, 300072, China.

PMID: 31782561
DOI: 10.1002/adma.201906122

Abstract

It is generally believed that the photoresponse behavior of organic field-effect transistors (OFETs) reflects the intrinsic property of organic semiconductors. However, this photoresponse hinders the application of OFETs in transparent displays as driven circuits due to the current instability resulting from the threshold voltage shift under light illumination. It is necessary to relieve the photosensitivity of OFETs to keep the devices stable. 2,6-diphenyl anthracene thin-film and single-crystal OFETs are fabricated on different substrates, and it is found that the degree of molecular order in the conducting channels and the defects at the dielectric/semiconductor interface play important roles in determining the phototransistor performance. When highly ordered single-crystal OFETs are fabricated on polymeric substrates with low defects, the photosensitivity (P) decreases by more than 10⁵ times and the threshold voltage shift (ΔV_T ) is almost eliminated compared with the corresponding thin-film OFETs. This phenomenon is further verified by using another three organic semiconductors for similar characterizations. The decreased P and ΔV_T of OFETs ensure a good current stability for OFETs to drive organic light-emitting diodes efficiently, which is essential to the application of OFETs in flexible and transparent displays.

Keywords: defects; organic field-effect transistors; photosensitivity; threshold voltage shift.

Abstract

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