Optoelectronic Properties of a van der Waals WS2 Monolayer/2D Perovskite Vertical Heterostructure

• Published in: ACS applied materials & interfaces Vol. 12; no. 40; pp. 45235 - 45242
• Main Authors: Wang, Qixing, Zhang, Qi, Luo, Xin, Wang, Junyong, Zhu, Rui, Liang, Qijie, Zhang, Lei, Yong, Justin Zhou, Yu Wong, Calvin Pei, Eda, Goki, Smet, Jurgen H, Wee, Andrew T. S
• Format: Journal Article
• Language: English
• Published: American Chemical Society 07.10.2020
• Subjects: disulfides; electric potential difference; Functional Nanostructured Materials (including low-D carbon); geometry; graphene; photovoltaic cells; tungsten; van der Waals forces; self-driven photodetector; heterostructure; 2D perovskite; WS2; photovoltaic effect
• ISSN: 1944-8244; 1944-8252; 1944-8252
• DOI: 10.1021/acsami.0c14398

Two-dimensional (2D) Ruddlesden–Popper perovskites have been demonstrated to possess great potential for optical and optoelectronic devices. Because they exhibit better ambient stability than three-dimensional (3D) perovskites, they have been considered as potential substitutes for 3D perovskites as light absorbing layers to improve the photoresponsivity of monolayer transition metal dichalcogenide (TMDC)-based photodetectors. Investigation of the optoelectronic properties of TMDC monolayer/2D perovskite vertical heterostructures is however at an early stage. Here, we address the photovoltaic effect and the photodetection performance in tungsten disulfide (WS2) monolayer/2D perovskite (C6H5C2H4NH3)2PbI4 (PEPI) vertical heterostructures. A vertical device geometry with separate graphene contacts to both heterointerface constituents acted as a photovoltaic device and self-driven photodetector. The photovoltaic device exhibited an open circuit voltage of −0.57 V and a short circuit current of 41.6 nA. A photoresponsivity of 0.13 mA/W at the WS2/PEPI heterointerface was achieved, which was signified by a factor of 5 compared to that from the individual WS2 region. The current on/off ratio of the self-driven photodetector was approximately 1500. The photoresponsivity and external quantum efficiency of the self-driven photodetector were estimated to be 24.2 μA/W and 5.7 × 10–5, respectively. This work corroborates that 2D perovskites are promising light absorbing layers in optoelectronic devices with a TMDC-based heterointerface.