Band Structure Engineering of Interfacial Semiconductors Based on Atomically Thin Lead Iodide Crystals

Yan Sun; Zishu Zhou; Zhen Huang; Jiangbin Wu; Liujiang Zhou; Yang Cheng; Jinqiu Liu; Chao Zhu; Maotao Yu; Peng Yu; Wei Zhu; Yue Liu; Jian Zhou; Bowen Liu; Hongguang Xie; Yi Cao; Hai Li; Xinran Wang; Kaihui Liu; Xiaoyong Wang; Jianpu Wang; Lin Wang; Wei Huang

doi:10.1002/adma.201806562

Band Structure Engineering of Interfacial Semiconductors Based on Atomically Thin Lead Iodide Crystals

Adv Mater. 2019 Apr;31(17):e1806562. doi: 10.1002/adma.201806562. Epub 2019 Mar 12.

Authors

Yan Sun¹, Zishu Zhou¹, Zhen Huang¹, Jiangbin Wu², Liujiang Zhou³, Yang Cheng⁴, Jinqiu Liu⁵, Chao Zhu⁶, Maotao Yu¹, Peng Yu⁷, Wei Zhu³, Yue Liu¹, Jian Zhou⁸, Bowen Liu¹, Hongguang Xie¹, Yi Cao¹, Hai Li¹, Xinran Wang⁸, Kaihui Liu⁴, Xiaoyong Wang⁵, Jianpu Wang¹, Lin Wang¹, Wei Huang^{1

9}

Affiliations

¹ Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing, 211816, China.
² Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA, 90089, USA.
³ Center for Nonlinear Studies and Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
⁴ State Key Laboratory for Mesoscopic Physics, School of Physics Department, Peking University, Beijing, 100871, China.
⁵ National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China.
⁶ Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
⁷ School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, China.
⁸ National Laboratory of Solid-State Microstructures School of Electronic Science and Engineering Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
⁹ Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, 710072, Shaanxi, China.

PMID: 30861234
DOI: 10.1002/adma.201806562

Abstract

To explore new constituents in two-dimensional (2D) materials and to combine their best in van der Waals heterostructures is in great demand as being a unique platform to discover new physical phenomena and to design novel functionalities in interface-based devices. Herein, PbI₂ crystals as thin as a few layers are synthesized, particularly through a facile low-temperature solution approach with crystals of large size, regular shape, different thicknesses, and high yields. As a prototypical demonstration of band engineering of PbI₂ -based interfacial semiconductors, PbI₂ crystals are assembled with several transition metal dichalcogenide monolayers. The photoluminescence of MoS₂ is enhanced in MoS₂ /PbI₂ stacks, while a dramatic photoluminescence quenching of WS₂ and WSe₂ is revealed in WS₂ /PbI₂ and WSe₂ /PbI₂ stacks. This is attributed to the effective heterojunction formation between PbI₂ and these monolayers; type I band alignment in MoS₂ /PbI₂ stacks, where fast-transferred charge carriers accumulate in MoS₂ with high emission efficiency, results in photoluminescence enhancement, and type II in WS₂ /PbI₂ and WSe₂ /PbI₂ stacks, with separated electrons and holes suitable for light harvesting, results in photoluminescence quenching. The results demonstrate that MoS₂ , WS₂ , and WSe₂ monolayers with similar electronic structures show completely distinct light-matter interactions when interfacing with PbI₂ , providing unprecedented capabilities to engineer the device performance of 2D heterostructures.

Keywords: 2D materials; band alignment; heterostructures; interlayer interactions; lead iodide.

Abstract

Grants and funding