Blueshift Enhanced Giant Lateral Photovoltaic Effect Observed in MoS₂ Granular Film (Quantum Dots)/Porous Silicon/p-Si

The lateral photovoltaic effect (LPE) has garnered significant attention due to its extensive applications in fields such as position-sensitive detectors, artificial intelligence, imaging, automatic driving, and so on. Enhancing LPE sensitivity has long been a focal point for researchers, with recent years showing advancements but still leaving room for improvement. In this study, we achieved sensitivities of up to 1195.02 mV/mm for MoS₂ granular film (MoS₂-GF)/porous silicon (PS)/p-Si and 951.71 mV/mm for MoS₂-QDs/PS/p-Si structures under 520 nm laser irradiation. The results demonstrate sensitivities 1 to 3 orders of magnitude higher than those of traditional LPE devices and surpass the majority of previously reported position-sensitive detectors. Leveraging the enhanced light absorption in PS, we observed a blueshift due to multiple excitonic transitions induced by the quantum confinement effects of MoS₂ granular films and quantum dots, assisting the light response of LPE. By forming heterojunctions and serving as carrier mediators, they effectively suppress carrier recombination of photogenerated carriers and holes on the PS surface, thereby enhancing utilization efficiency. Furthermore, they extend the short carrier migration length caused by the irregular surface of PS, promoting lateral diffusion of photogenerated carriers and generating significant lateral concentration gradients. The advancements present novel pathways for ultrawideband and ultrasensitive optoelectronic and position-sensitive detectors, underscoring their vast potential in diverse optoelectronic applications.