Modulated interlayer charge transfer dynamics in a monolayer TMD/metal junction. Issue 2 (13th December 2018)

• Record Type: Journal Article
• Authors: Zhang, Linglong; Yan, Han; Sun, Xueqian; Dong, Miheng; Yildirim, Tanju; Wang, Bowen; Wen, Bo; Neupane, Guru Prakash; Sharma, Ankur; Zhu, Yi; Zhang, Jian; Liang, Kun; Liu, Boqing; Nguyen, Hieu T.; Macdonald, Daniel; Lu, Yuerui
• Is Part Of: Nanoscale. Volume 11:Issue 2(2019)
• Page Start: 418
• Page End: 425
• Publication Date: 2018-12-13
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c8nr08728h
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : The interlayer interactions and coupling of mTMD–metal junction determine the performance of the corresponding optoelectronic devices. Abstract : The performance of optoelectronic devices based on monolayer transition-metal dichalcogenide (mTMD) semiconductors is significantly affected by the contact at the mTMD–metal interface, which is dependent on interlayer interactions and coupling. Here, we report a systematic optical method to investigate the interlayer charge transfer and coupling in a mTMD–metal heterojunction. Giant photoluminescence (PL) quenching was observed in a monolayer MoS2 /Pd (1L MoS2 /Pd) junction which is mainly due to the efficient interlayer charge transfer between Pd and MoS2 . 1L MoS2 /Pd also exhibits an increase in the PL quenching factor ( η ) as the temperature decreases, due to a reduction of the interlayer spacing. Annealing experiments were also performed which supported interlayer charge transfer as the main mechanism for the increase of η . Moreover, a monolayer MoS2 /Au (1L MoS2 /Au) junction was fabricated for engineering the interlayer charge transfer. Interestingly, a narrowing effect of the full width at half maximum (FWHM) was encountered as the junctions changed from 1L MoS2 /SiO2 → 1L MoS2 /Au → 1L MoS2 /Pd, possibly originating from a change of the doping level induced weakening of exciton-carrier scattering. Our results deepen the understanding of metal–semiconductor junctions for further exploring fundamental phenomena and enabling high-performance devices using mTMD–metal junctions.