Reversible photoluminescence modulation of monolayer MoS2 on a ferroelectric substrate by light irradiation and thermal annealing
Reversible photoluminescence modulation of monolayer MoS2 on a ferroelectric substrate by light irradiation and thermal annealing
复制标题
通过光照射和热退火对铁电衬底上单层 MoS2 进行可逆光致发光调制
DOI：
10.1039/d1cp02248b
复制
发表时间：
2021
影响因子：
3.3
通讯作者：
Gao Bo
中科院分区：
文献类型：
--
作者：
Wang Peng;Wang Jian;Zheng Yun;Shi Hongyan;Sun Xiudong;Liu Wenjun;Gao Bo
单层半导体二维（2D）材料由于其独特的结构对称性和能带结构而成为研究自旋谷耦合效应和制备新型光电器件的新兴材料。由于它们的原子厚度，它们的激子光学响应对介电环境高度敏感。在这项工作中，我们提出了一种新的方法来可逆地调制单层二硫化钼（MoS 2）的光学性能，通过改变基板的介电性能，通过激光照射和热退火。我们选择LiNbO 3作为衬底，记录了单层MoS 2在LiNbO 3衬底上具有正（P+）和负（P-）铁电极性的PL谱。由于表面电荷的反向掺杂，观察到A峰的明显PL强度。在光照射下，MoS 2在P+ Fe 2 O3掺杂的LiNbO 3上的发光强度随着时间的推移逐渐降低，这是由于本征p掺杂的减少，这源于光激发电子在自发极化场下的漂移和在表面的积累。发现通过热退火可以恢复PL强度，这可以消除电荷重新分布。这项研究提供了一种策略，可逆地调制单层的铁电材料顶部的二维材料的光学性质。
Monolayer semiconducting two-dimensional (2D) materials are strongly emerging materials for exploring the spin-valley coupling effect and fabricating novel optoelectronic devices due to their unique structural symmetry and band structures. Due to their atomic thickness, their excitonic optical response is highly sensitive to the dielectric environment. In this work, we present a novel approach to reversibly modulate the optical properties of monolayer molybdenum disulfide (MoS2) via changing the dielectric properties of the substrate by laser irradiation and thermal annealing. We chose LiNbO3 as the substrate and recorded the PL spectra of monolayer MoS2 on LiNbO3 substrates with positive (P+) and negative (P−) ferroelectric polarities. A distinct PL intensity of the A peak was observed due to opposite doping by surface charges. Under light irradiation, the PL intensity of monolayer MoS2 on P+ Fe2O3-doped LiNbO3 gradually decreased with time due to the reduction of intrinsic p-doping, which originated from the drift of photo-excited electrons under a spontaneous polarization field and accumulation on the surface. The PL intensity was found to be restored by thermal annealing which could erase the charge redistribution. This study provides a strategy to reversibly modulate the optical properties of monolayer 2D materials on top of ferroelectric materials.