Observation of the photovoltaic effect in a van der Waals heterostructure
Observation of the photovoltaic effect in a van der Waals heterostructure
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范德华异质结构中光伏效应的观察
DOI：
10.1039/d2nr06616e
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发表时间：
2023
期刊：
影响因子：
6.7
通讯作者：
Kitaura Ryo
中科院分区：
文献类型：
--
作者：
Zhang Shaochun;Maruyama Mina;Okada Susumu;Xue Mengsong;Watanabe Kenji;Taniguchi Takashi;Hashimoto Kazuki;Miyata Yasumitsu;Canton-Vitoria Ruben;Kitaura Ryo
范德华(VDW)异质结构可以由各种二维材料组装而成，为探索突发现象提供了一个通用的平台。在这里，我们报道了在WS2/MoS2VDW异质结中观察到的光伏效应。WS_2/MoS_2在波长633 nm处的光激发在不加偏置电压的情况下产生光电流，光电流的激发功率依赖关系表现出从线性到平方根的特征交叉。光电流图清楚地表明，观察到的光伏效应来自WS2/MoS2区域，而不是电极接触处的肖特基结。开尔文探针显微镜观察显示，静电势没有斜率，排除了光电流来自无意中形成的内置电势的可能性。
van der Waals (vdW) heterostructures, which can be assembled with various two-dimensional materials, provide a versatile platform for exploring emergent phenomena. Here, we report an observation of the photovoltaic effect in a WS2/MoS2 vdW heterostructure. Light excitation of WS2/MoS2 at a wavelength of 633 nm yields a photocurrent without applying bias voltages, and the excitation power dependence of the photocurrent shows characteristic crossover from a linear to square root dependence. Photocurrent mapping has clearly shown that the observed photovoltaic effect arises from the WS2/MoS2 region, not from Schottky junctions at electrode contacts. Kelvin probe microscopy observations show no slope in the electrostatic potential, excluding the possibility that the photocurrent originates from an unintentionally formed built-in potential.