Interfacially assembled MXene (Ti3C2Tx)/Si Schottky junction tailored for high-performance self-powered white light detection in smart indoor networks

Abstract

MXenes are a new class of 2D materials with alluring attributes for electronic applications. However, their integration into 3D semiconductor devices faces challenges like fabrication complexity and poor interfacial quality. This study presents a Ti₃C₂T_x MXene/n-Si van der Waals Schottky junction-based self-powered white light photodetector with a simple solution-based assembly of MXene on a pre-patterned n-Si substrate. An atomic layer-deposited Al₂O₃ dielectric film is used at the interface as an electron-blocking layer to reduce the charge recombination. Additionally, a novel chemical modification approach using InCl₃ is presented, producing a highly conducting MXene film with an increased work function (∼0.4 eV). As a result, the photodetector achieves a responsivity of 134 mA W⁻¹, which is 13 times higher than that of the pristine MXene/Si device, and a specific detectivity of 1.38 × 10¹² Jones, with stable performance across low-high light intensities. The device works with self-powered mode under white light with an impressive open-circuit voltage of 400 mV. Further, the device is integrated as a self-powered optical receiver in a wireless communication system, enabling rapid indoor data transmission. The potential of surface chemistry and interfacial engineering in enhancing the performance of MXene-based devices is evidenced, opening the avenues for its use in next-generation electronic technologies.