Editable Light Response in Halide Perovskites Encapsulated within Single-Walled Carbon Nanotubes.

Abstract

One-dimensional (1D) perovskite heterostructures fabricated through the template method employing single-walled carbon nanotubes (SWCNTs) have garnered significant attention due to their distinctive structural properties. Nevertheless, substantial challenges remain in the device applications of 1D halide perovskite heterostructures due to the separation issue of the semiconductor SWCNTs (s-SWCNTs) after encapsulating the perovskite. Here, we report 1D perovskite heterostructures based on CsPbBr₃ encapsulated inside s-SWCNTs (CPB@s-SWCNTs), realizing editable photoresponse. 1D perovskite heterostructures were verified by high-angle annular dark-field scanning transmission electron microscopy. The CPB-filled s-SWCNTs were successfully separated, achieving a significant n-doping effect and a weak negative response. Density functional theory calculations show that electrons are transferred from the CPB to SWCNTs at 0.61 e per SWCNT unit cell. Kelvin probe force microscopy shows that the surface potential of CPB@s-SWCNTs is higher than that of s-SWCNTs. The integrated CPB@s-SWCNTs film, when coupled with a GaN wafer device, demonstrates an editable photoresponse, including enhanced negative response (n-GaN), asymmetric positive response (p-GaN), and ultrahigh photoresponse at 0 V. This study provides an effective strategy for fabricating large-area s-SWCNTs films filled with various perovskite materials, thereby broadening the application of 1D van der Waals heterostructures in optoelectronic devices.