標題: Lateral amorphous selenium metal-insulator-semiconductor-insulator-metal photodetectors using ultrathin dielectric blocking layers for dark current suppression
作者: Chang, Cheng-Yi
Pan, Fu-Ming
Lin, Jian-Siang
Yu, Tung-Yuan
Li, Yi-Ming
Chen, Chieh-Yang
材料科學與工程學系
電機工程學系
Department of Materials Science and Engineering
Department of Electrical and Computer Engineering
公開日期: 21-Dec-2016
摘要: We fabricated amorphous selenium (a-Se) photodetectors with a lateral metal-insulator-semiconductor-insulator-metal (MISIM) device structure. Thermal aluminum oxide, plasma-enhanced chemical vapor deposited silicon nitride, and thermal atomic layer deposited (ALD) aluminum oxide and hafnium oxide (ALD-HfO2) were used as the electron and hole blocking layers of the MISIM photodetectors for dark current suppression. A reduction in the dark current by three orders of magnitude can be achieved at electric fields between 10 and 30 V/mu m. The effective dark current suppression is primarily ascribed to electric field lowering in the dielectric layers as a result of charge trapping in deep levels. Photogenerated carriers in the a-Se layer can be transported across the blocking layers to the Al electrodes via Fowler-Nordheim tunneling because a high electric field develops in the ultrathin dielectric layers under illumination. Since the a-Se MISIM photodetectors have a very low dark current without significant degradation in the photoresponse, the signal contrast is greatly improved. The MISIM photodetector with the ALD-HfO2 blocking layer has an optimal signal contrast more than 500 times the contrast of the photodetector without a blocking layer at 15 V/mu m. Published by AIP Publishing.
URI: http://dx.doi.org/10.1063/1.4972029
http://hdl.handle.net/11536/133076
ISSN: 0021-8979
DOI: 10.1063/1.4972029
期刊: JOURNAL OF APPLIED PHYSICS
Volume: 120
Issue: 23
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