Metastability effect in solar blind UV amorphous silicon carbide photodetector

We present a study of the behavior under illumination of an ultraviolet detector based on a hydrogenated amorphous silicon and silicon carbide p-i-n heterostructure. An efficiency (around 80%) is obtained at 50 nm together with a visible rejection. We found that under ultraviolet illumination the photocurrent increases to three times the initial value, whereas it remains almost constant under visible light. This behavior is ascribed to the light activation of baron dopant in the p-layer and is investigated by a simple equivalent circuit of the structure. This model can be utilized to optimize the geometry of the metal grid and thus the performance of the device. (C) 1998 Elsevier Science B.V. All rights reserved.