Enhanced photoresponse of highly air-stable palladium diselenide by thickness engineering

Nanophotonics

article

Jing Wu¹  Yunshan Zhao²  Minglei Sun³  Minrui Zheng²  Gang Zhang⁴  Xinke Liu⁵  Dongzhi Chi¹ 

[1] Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research);Department of Electrical and Computer Engineering, National University of Singapore;School of Mechanical Engineering, Southeast University;Institute of High Performance Computing, A*STAR (Agency for Science, Technology and Research);College of Materials Science and Engineering, Shenzhen University

关键词: palladium diselenide;    photoresponsivity;    photodetector;    band convergence;   

DOI  :  10.1515/nanoph-2019-0542

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Recently, layered two-dimensional (2D) palladium diselenide (PdSe 2 ), 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, PdSe 2 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 PdSe 2 are still lacking up to date. Herein, we studied the optoelectronics transport characteristics of high-quality PdSe 2 -based photodetectors with different thicknesses. We demonstrated an enhancement of PdSe 2 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 PdSe 2 , in agreement with first-principles calculation. Our results offer new insight into the layer-dependent optoelectronic properties of PdSe 2 and open new avenues in engineering next-generation 2D-based electronics and optoelectronics.

【 授权许可】

CC BY