Efficient and Layer-Dependent Exciton Pumping across Atomically Thin Organic-Inorganic Type-I Heterostructures

Linglong Zhang; Ankur Sharma; Yi Zhu; Yuhan Zhang; Bowen Wang; Miheng Dong; Hieu T Nguyen; Zhu Wang; Bo Wen; Yujie Cao; Boqing Liu; Xueqian Sun; Jiong Yang; Ziyuan Li; Arara Kar; Yi Shi; Daniel Macdonald; Zongfu Yu; Xinran Wang; Yuerui Lu

doi:10.1002/adma.201803986

Efficient and Layer-Dependent Exciton Pumping across Atomically Thin Organic-Inorganic Type-I Heterostructures

Adv Mater. 2018 Aug 30:e1803986. doi: 10.1002/adma.201803986. Online ahead of print.

Authors

Linglong Zhang^{1

2}, Ankur Sharma², Yi Zhu², Yuhan Zhang¹, Bowen Wang², Miheng Dong², Hieu T Nguyen², Zhu Wang³, Bo Wen², Yujie Cao¹, Boqing Liu², Xueqian Sun², Jiong Yang², Ziyuan Li⁴, Arara Kar², Yi Shi¹, Daniel Macdonald², Zongfu Yu³, Xinran Wang¹, Yuerui Lu^{2

5}

Affiliations

¹ National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, P. R. China.
² Research School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory, 2601, Australia.
³ Department of Electrical and Computer Engineering, University of Wisconsin, Madison, WI, 53706, USA.
⁴ Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, 2601, ACT, Australia.
⁵ ARC Centre of Excellence in Future Low-Energy, Electronics Technologies (FLEET), ANU node, Canberra, Australian Capital Territory, 2601, Australia.

PMID: 30159929
DOI: 10.1002/adma.201803986

Abstract

The fundamental light-matter interactions in monolayer transition metal dichalcogenides might be significantly engineered by hybridization with their organic counterparts, enabling intriguing optoelectronic applications. Here, atomically thin organic-inorganic (O-I) heterostructures, comprising monolayer MoSe₂ and mono-/few-layer single-crystal pentacene samples, are fabricated. These heterostructures show type-I band alignments, allowing efficient and layer-dependent exciton pumping across the O-I interfaces. The interfacial exciton pumping has much higher efficiency (>86 times) than the photoexcitation process in MoSe₂ , although the pentacene layer has much lower optical absorption than MoSe₂ . This highly enhanced pumping efficiency is attributed to the high quantum yield in pentacene and the ultrafast energy transfer between the O-I interface. Furthermore, those organic counterparts significantly modulate the bindings of charged excitons in monolayer MoSe₂ via their precise dielectric environment engineering. The results open new avenues for exploring fundamental phenomena and novel optoelectronic applications using atomically thin O-I heterostructures.

Keywords: 2D materials; binding energy; exciton pumping; organic-inorganic; type-I heterostructures.