In situ growth of a 2D assisted passivation layer enabling high-performance and stable 2D/3D stacked perovskite photodetectors for visible light communication applications

Abstract

Two-dimensional (2D) perovskites have shown more considerable advantages in terms of stability than their three-dimensional (3D) counterparts. However, the intrinsic poor light absorption and charge transport capacity impede the improvement of device performance. Herein a novel 2D perovskite material containing butylammonium acetate (BAAc) is firstly introduced to fabricate high-performance and stable 2D/3D stacked perovskite photodetectors (PPDs). With the in situ growth of BAAc, the defects on the surfaces and grain boundaries of regular 3D perovskite (3D-PSK) films are dramatically passivated, and the larger size of long-chain BA⁺ ions not only enhances the moisture stability but also improves the thermal stability of the 2D/3D stacked perovskite films and PPDs. As a result, the responsivity of the BAAc treated PPD (BAAc-PPD) reaches 2.11 A W⁻¹ under the illumination of a 532 nm laser, and retains 78.5% of the initial value after 20 days of nonencapsulated storage at 10–15% relative humidity (RH). In addition, we successfully demonstrate the use of our PPDs in a visible light communication system. Our work provides a simple and effective method for the fabrication of high-performance and stable 2D/3D stacked PPDs, which has great application potential in visible light communication, imaging and environmental monitoring under complex environmental conditions.