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

Nanophotonics

卷:9

Liu Xinke¹  Zhao Yunshan²  Zheng Minrui²  Zhang Gang³  Wu Jing⁴  Chi Dongzhi⁴  Sun Minglei⁵ 

[1] College of Materials Science and Engineering, Shenzhen University, 3688 Nanhai Ave, Shenzhen 518060, PR China;

[2] Department of Electrical and Computer Engineering, National University of Singapore, 117583 Singapore, Singapore;

[3] Institute of High Performance Computing, A*STAR (Agency for Science, Technology and Research), 1 Fusionopolis Way, 138632 Singapore, Singapore;

[4] Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Innovis, 08‐03, 138634 Singapore, Singapore;

[5] School of Mechanical Engineering, Southeast University, Nanjing, Jiangsu 211189, China;

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

DOI  :  10.1515/nanoph-2019-0542

来源: DOAJ

【 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.

【 授权许可】

Unknown