Transient lateral photovoltaic effect observed in Ti–SiO2–Si structure

Abstract

The transient response of the lateral photovoltaic effect (LPE) was observed when Ti–SiO2–Si structure was irradiated by a 650 nm laser which is attributed to the remarkable absorptivity. LPE is linearly dependent on the laser irradiation position. The LPE has high sensitivity of 68.4 mV/mm and linearity of 0.9853, respectively. This paper focuses on the transient response process of LPE at different laser irradiation positions. The mechanism of the response time of the MOS structure is caused by the diffusion of electrons to the positive and negative electrodes. We experimentally verified this mechanism by laser irradiation on different positions. The principle of transient LPE is revealed by carrier diffusion and recombination theory. LPE has faster response time and larger amplitude when the laser irradiation points are close to electrodes. A resistor–capacitor (RC) circuit model combines with LPE which is established to simulate and analyze the transient process. The research provides a new direction for LPE-based sensors with regard to the amplitude and response time which change with laser irradiation position in Ti–SiO2–Si structure for researchers to develop position-sensitive sensors.