Energy Level Matching and Band Edge Reconfiguration for Enhanced Charge Transport in Dion-Jacobson 3D/2D Perovskite Heterojunctions

Zhi Fang; Ming-Hui Shang; Yapeng Zheng; Qian Sun; Yong Xu; Xinmei Hou; Weiyou Yang

doi:10.1021/acs.jpclett.3c01303

Energy Level Matching and Band Edge Reconfiguration for Enhanced Charge Transport in Dion-Jacobson 3D/2D Perovskite Heterojunctions

J Phys Chem Lett. 2023 Jul 27;14(29):6592-6600. doi: 10.1021/acs.jpclett.3c01303. Epub 2023 Jul 17.

Authors

Zhi Fang^{1

2

3}, Ming-Hui Shang^{1

4}, Yapeng Zheng^{1

2}, Qian Sun^{1

2}, Yong Xu¹, Xinmei Hou², Weiyou Yang¹

Affiliations

¹ Institute of Micro/Nano Materials and Devices, Ningbo University of Technology, Ningbo City, 315211, P. R. China.
² Innovation Research Institute for Carbon Neutrality, University of Science and Technology Beijing, Beijing 100083, P. R. China.
³ Beijing Key Laboratory for Magnetoelectric Materials and Devices (BKL-MMD), Beijing Innovation Centre for Engineering Science and Advanced Technology (BIC-ESAT), School of Materials Science and Engineering, Peking University, Beijing 100871, P. R. China.
⁴ Graduate school of Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan.

PMID: 37459115
DOI: 10.1021/acs.jpclett.3c01303

Abstract

Generally, the 2D CsPbI₃ layer capping on 3D counterparts has been considered as an effective strategy for both enhancing photovoltaic efficiency and stability. However, the intrinsically poor out-of-plane charge transport through the 2D layer remarkably hinders the overall performance of solar devices. To overcome such a challenge, we report the rationally designed 3D-CsPbI₃/2D-(PY_n)PbI₄ (n = 1-4) heterojunctions with desirable energy level matching. It is evidenced that the valence band (VB) edge reconfiguration would occur with the increase of n, accompanied by the VB maximum (VBM) of the 2D component moving down from the higher level above that of the 3D component to the underneath. Consequently, the as-constructed 3D/2D-(PY_n)PbI₄ (n = 1, 2) heterojunctions exhibit optimal energy level matching, with accelerated transport of holes from 3D to 2D component and limited backflow of electrons. These findings might provide some meaningful insights on the energy level matching in 3D/2D perovskite heterojunctions.