文章基本信息

标题：Enhanced photoresponse of highly air-stable palladium diselenide by thickness engineering
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作者：Jing Wu ; Yunshan Zhao ; Minglei Sun 等
期刊名称：Nanophotonics
印刷版ISSN：2192-8606
电子版ISSN：2192-8614
出版年度：2020
卷号：9
期号：8
页码：2467-2474
DOI：10.1515/nanoph-2019-0542
出版社：Walter de Gruyter GmbH
摘要：Recently, layered two-dimensional (2D) palladium diselenide (PdSe2 ), with a unique low- symmetry puckered pentagon atomic morphology, has emerged as a promising candidate for next-generation nanoelectronics and optoelectronics because of its chemical stability and extraordinary electrical properties. Moreover, PdSe2 possesses a strong thickness-dependent bandgap that varies from 0 eV for bulk to 1.3 eV for monolayer, which can further render its potential applications in optoelectronics. However, the layer-dependent optoelectronic properties of PdSe2 are still lacking up to date. Herein, we studied the optoelectronics transport characteristics of high-quality PdSe2 -based photodetectors with different thicknesses. We demonstrated an enhancement of PdSe2 photodetector performance owing to the band engineering via a thickness reduction. The highest responsivity of 5.35 A/W can be achieved with an external quantum efficiency of 1250% at the wavelength of 532 nm. We attribute such high performance in photoresponsivity to the high valley convergence in the conduction band of layered PdSe2 , in agreement with first-principles calculation. Our results offer new insight into the layer-dependent optoelectronic properties of PdSe2 and open new avenues in engineering next-generation 2D-based electronics and optoelectronics.
关键词：palladium diselenide ; photoresponsivity ; photodetector ; band convergence