Nonvolatile Electric Control of Exciton Complexes in Monolayer MoSe2 with Two-Dimensional Ferroelectric CuInP2S6

Xiaoyu Mao; Jun Fu; Chen Chen; Yue Li; Heng Liu; Ming Gong; Hualing Zeng

doi:10.1021/acsami.1c03067

Nonvolatile Electric Control of Exciton Complexes in Monolayer MoSe₂ with Two-Dimensional Ferroelectric CuInP₂S₆

ACS Appl Mater Interfaces. 2021 May 26;13(20):24250-24257. doi: 10.1021/acsami.1c03067. Epub 2021 May 11.

Authors

Xiaoyu Mao^{1

2}, Jun Fu^{1

2}, Chen Chen^{1

2}, Yue Li^{1

2}, Heng Liu^{1

2}, Ming Gong^{3

4}, Hualing Zeng^{1

2}

Affiliations

¹ International Center for Quantum Design of Functional Materials (ICQD), Hefei National Laboratory for Physical Science at the Microscale, and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
² Key Laboratory of Strongly-Coupled Quantum Matter Physics, Department of Physics, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China.
³ CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, People's Republic of China.
⁴ Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.

PMID: 33974385
DOI: 10.1021/acsami.1c03067

Abstract

Monolayer transition-metal dichalcogenides (TMDs) have provided a platform to investigate the excitonic states at the two-dimensional (2D) limit. The inherent properties of excitons in TMDs, such as the photoluminescence quantum yield, the charge states, and even the binding energy, can be effectively controlled via electrostatic gating, selective carrier doping, or substrate dielectric engineering. Here, aiming for the nonvolatile electrical tunability of excitonic states and thereby the optical property of TMDs, we demonstrate a 2D ferroelectric heterostructure with monolayer MoSe₂ and ultrathin CuInP₂S₆ (CIPS). In the heterostructure, the electric polarization of CIPS results in continuous, global, and large electronic modulation in monolayer MoSe₂. With the saturated ferroelectric polarization of CIPS, electron-doped or hole-doped MoSe₂ is realized in a single device. The carrier density tunability in the heterostructure is as high as 5 × 10¹² cm^-2. The nonvolatile behavior of these devices up to 3 months is also characterized. Our results provide a new and practical strategy for low-power consumption and agelong tunable optoelectronic devices.

Keywords: 2D ferroelectric heterostructure; CuInP2S6; MoSe2; exciton; ferroelectricity.