Pressure-Induced Schottky-Ohmic Contact Transition in Pt/Si Heterojunction Via Interfacial Barrier Modulation for Ultra-Enhanced Photocurrent Generation

Silicon-based optoelectronic devices represent a cornerstone of modern optoelectronics, owing to their low cost and mature fabrication infrastructure. Their performance optimization hinges critically on precise control of the Schottky barrier height (SBH). As a nondestructive, continuously tunable physical parameter, pressure offers a novel strategy for dynamic SBH modulation. Here, we employed high-pressure techniques to investigate Pt/Si Schottky junctions. With increasing pressure, the SBH decreased monotonically from 0.713 to 0.446 eV at a rate of -165.8 meV/GPa and was completely eliminated above 4.3 GPa, indicating a pressure-driven Schottky-to-Ohmic transition. Mechanistic analysis revealed that pressure modulates SBH primarily by regulating interfacial gap state density and reconstructing the band structure. This transition led to a drastically enhanced photoresponse, with photocurrent intensities increasing by 100-fold and 3400-fold under 532 and 660 nm laser excitation, respectively. This work elucidates the pressure-tuning behavior of silicon-based Schottky junctions and their regulatory mechanism on photoelectric performance, providing a new strategy for the design of high-performance silicon optoelectronic devices.