Novel silicon-rich SiO2 photoconductor

The photocurrent analysis of a metal-semiconductor-metal photoconductors (MSM-PD) with interdigitated electrodes fabricated on silicon-ion-implanted Borosilicate glass substrate is reported. The dark- and photo-current of the SiO2:Si+ MSM-PD with finger width and spacing of 5 micrometers are 72 pA and 447 pA at bias of 50 volts, which corresponds to a photocurrent gain of 5.2 and a responsivity of 0.38 (mu) A/W as measured under the injection power of 25mW at 514.5 nm. The decreasing trend in photocurrent response versus wavelength reveals that the absorption coefficient of the SiO2:Si+ becomes smaller at longer wavelengths.