High-Performance Broadband Photodetector Based on Monolayer MoS2 Hybridized with Environment-Friendly CuInSe2 Quantum Dots

Tao Shen; Feng Li; Zhenyun Zhang; Lei Xu; Junjie Qi

doi:10.1021/acsami.0c14161

High-Performance Broadband Photodetector Based on Monolayer MoS₂ Hybridized with Environment-Friendly CuInSe₂ Quantum Dots

ACS Appl Mater Interfaces. 2020 Dec 9;12(49):54927-54935. doi: 10.1021/acsami.0c14161. Epub 2020 Nov 25.

Authors

Tao Shen¹, Feng Li², Zhenyun Zhang¹, Lei Xu¹, Junjie Qi¹

Affiliations

¹ School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China.
² International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, People's Republic of China.

PMID: 33238704
DOI: 10.1021/acsami.0c14161

Abstract

Monolayer MoS₂, a direct bandgap transition metal dichalcogenide (TMD), has attracted worldwide attention in electronics and optoelectronics. However, the performance of photodetectors based on monolayer MoS₂ is restricted to a weak optical absorption, narrow absorption range, and persistent photoconductance. Herein, benefiting from an easy solution process, high light absorption coefficient, and wide absorption range, environment-friendly CuInSe₂ quantum dots (QDs) are hybridized with monolayer MoS₂ for high-performance broadband photodetectors. Owing to the favorable type-II energy band alignment of MoS₂/CuInSe₂-QDs, the hybrid photodetector exhibits a broadband photoresponse from the ultraviolet to near-infrared region, with an ultrahigh photoresponsivity of 74.8 A/W at 1064 nm, and compared with those of the pristine MoS₂ device, the photoresponsivity and specific detectivity in the ultraviolet-visible region were enhanced by about 30 and 20 times, respectively. Furthermore, the formed depletion region at the MoS₂/CuInSe₂-QDs interface can significantly increase the photoresponse speed, and the accumulated holes in the QD side induce a strong photogating effect to improve the photoresponsive characteristics of the hybrid photodetector. Our work opens up opportunities for fabricating high-performance monolayer TMD-based broadband photodetectors.

Keywords: 2D MoS2; CuInSe2-QDs; charge transfer; photodetection; van der Waals heterostructure.