Two dimensional image sensors based on amorphous silicon alloy p-i-n diodes

Abstract Two-dimensional amorphous silicon alloy image sensors have been developed. We have built a demonstration device on a 9×9cm 2 area, having a 500μm pixel pitch. The pixel is based on a TCO-p-i-n-i-p-Metal structure. The p-i-n photodiodes (PD) are the photo-sensing elements and are stacked and back-to-back connected to n-i-p blocking diodes (BD), which perform the addressing and the connection of the PDs to a data bus. Due to an optimization of the thickness and of the energy gap of the a-Si:H layers, we obtained a rectification ratio I f /I r ≈10 4 between the current levels in forward (I f ) and reverse (I r ) bias conditions, under 100lux green illumination. The binary detection of a light level has been performed at a scanning rate of 5.4 Mpixel/sec.