Potential Superiority of p-Type Silicon-Based Metal–Oxide–Semiconductor Structures Over n-Type for Lateral Photovoltaic Effects

In this letter, an unexpected stronger lateral photovoltaic effect was observed in Ni/SiO
₂
/p-Si than in Ni/SiO
₂
/n-Si. The largest sensitivity is increased by more than four times, from 5.64 to 26.3 mV/mm. Besides, the lateral photovoltage polarity was reversed. A model based on continuity and diffusion equations indicates that this particular enhancement is due to the increasing number of hole-electron pairs crossing the irradiated region of the Ni/SiO
₂
/p-Si structures per unit time and per unit area. These findings challenge the classical view that a longer carrier lifetime must lead to higher sensitivity, and, therefore, open up new opportunities for p-Si-based, low-cost, high-precision position sensitive detectors.