Photoinduced on laterally spreading of space-chargeregion

Abstract

Photoinduced on lateral spreading along the surface of space-charge-region (SCR) of planar metal-semiconductor-metal (MSM) structures have been investigated. This purpose for the SCR of such a structure plays a key role in generating photocurrent and thus, in dc and/ or ac scheme, the wider SCR along the active surface is better from the efficiency point of view. To study the SCR along the surface of MSM structures, we prepared planar MSM structures leaving the undepleted region between the electrodes. We examined their SCR spreading through the photocurrent-bias voltage characteristics.The experimental results were compared with the numerical simulation using a quasi – ID model of such a planar structure. Since the depleted region along the surface would be much more sensitive to the incident illumination than the undepleted region, increase in bias causes the increase in the depletion width and thus detected photocurrent.