Ultraviolet photodetectors based on Si-Zn-SnO thin film transistors with a stacked channel structure and a patterned NiO capping layer

Autor: Rong-Ming Ko, Wei-Ting Chen, Hao-Che Cheng, Chien-Hung Wu, Chao-Yen Chang, Shui-Jinn Wang
Rok vydání: 2022
Předmět:
Zdroj: Japanese Journal of Applied Physics. 62:SC1006
ISSN: 1347-4065
0021-4922
DOI: 10.35848/1347-4065/aca33c
Popis: Ultraviolet photodetectors (UVPDs) based on Si-Zn-SnO (SZTO) thin-film transistors (TFTs) with a stacked dual-channel layer (DCL) structure with different carrier concentration and NiO capping layer (CL) to alleviate the trade-off between dark current (I dark) and photocurrent (I ph) are reported. Experimental results show that under 275 nm irradiation, the proposed SZTO TFT UVPD with a 30 nm thick upper layer stacked on a 50 nm thick channel layer and a patterned NiO CL exhibit excellent photoresponsivity and photosensitivity up to 1672 A W−1 and 1.03 × 107 A A−1, which is about 272 and 137 times higher than conventional 30 nm thick single-channel layer SZTO TFT. These improvements are due to the use of a DCL which forms a high-low junction to reduce the effective channel thickness and increasing the space for UV illumination and the use of NiO CL lowers the I dark and causes a considerable negative threshold voltage shift under UV irradiation to significantly boost the I ph.
Databáze: OpenAIRE
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