Giant lateral photovoltaic effect in Ag/porous silicon/Si structure for high-performance near-infrared detection

The lateral photovoltaic effect demonstrates versatility across various applications, including photodetectors, imaging, spectroscopy, biosensing, and environmental monitoring. Challenges arise from the low energy of near-infrared photons, regarded as a bottleneck for high-sensitivity photodetector development in this spectrum, limiting applications like optical fiber communication and image sensors. However, this study achieved a remarkable 720.57 mV/mm sensitivity for the lateral photovoltaic effect in the near-infrared region with a 980 nm laser irradiation on an Ag/Porous Silicon/Si structure. This sensitivity surpasses previous observations several to hundreds of times and even outperforms many other structures in the short-wavelength spectrum, further emphasizing its significance in this field. The use of a unique fluoro-amino electrolysis technique ensures consistent porosity, mitigating the adverse effects of photoluminescence. Combined with surface Ag, it induces local surface plasmon resonance and efficient plasmon coupling, markedly increasing electron density. This highly sensitive structure propels advancements in near-infrared photodetectors and Raman signal enhancement, establishing a robust foundation for potential applications in highly sensitive photodetectors and biological sensors.