An a-Si:H/a-Si,Ge:H bulk barrier phototransistor with a-SiC:H barrier enhancement layer for high-gain IR optical detector

The design and fabrication of a high-gain amorphous silicon/amorphous silicon germanium (a-Si:H/a-Si,Ge:H) bulk barrier phototransistor for infrared light detection applications are reported. The a-Si,Ge:H material featured a lower energy gap and is suitable for the absorption of longer wave light, but it also leads to a low breakdown voltage and high dark current. An additional a-SiC:H thin-film layer was used at the collector/base interface in the conventional amorphous bulk barrier phototransistor to enhance the function of the bulk barrier and obtain high optical gain.>