Ferro-Pyro-Phototronic Effect Enhanced Self-Powered UV Photodetectors Based on BaTiO3@MXene/4H-SiC Heterojunction

Abstract

Ferroelectric materials, known for their superior spontaneous polarization and pyroelectric and photovoltaic effects, offer a promising avenue for fabricating high-performance optoelectronic devices. Herein, we report an ultraviolet (UV) photodetector (PDs) based on BaTiO₃@MXene/4H-SiC heterostructure, with its photosensitive properties significantly boosted by the ferro-pyro-phototronic effect. In the detector, the incorporation of MXene nanosheets boosts the spontaneous ferroelectric polarization of BaTiO₃ nanocrystals, thereby strengthening the built-in electric field at the BaTiO₃/4H-SiC heterojunction. The resulted BaTiO₃@MXene/4H-SiC heterostructure can work in a self-biasing manner, with robust performances, including responsivity (∼187.74 mA/W), specific detectivity (∼6.52 × 10¹³ Jones), external quantum efficiency (∼75.07%), response/recovery time (∼74.3/122.7 μs) upon 310 nm light irradiation. Particularly, the superlinear increase of the photocurrent, which results from the hot-carrier multiplication in MXene nanosheets, allows the device to produce additional photocurrent under ultraviolet illumination. Theoretical analysis confirms that the surface modification of MXene nanosheets can effectively alter the length of the Ti–O bonds on BaTiO₃ nanocrystal surfaces, thus enhancing their spontaneous ferroelectric polarization. Being seamlessly integrated into an ultraviolet wireless communication system, the BaTiO₃@MXene/4H-SiC self-powered photodetector demonstrates promising application prospects in optoelectronic interconnection circuits. This study provides an optimization strategy for advanced BaTiO₃ nanocrystals toward future high-performance electronic and optoelectronic devices in existing applications.