Nanocrystalline Silicon Lateral MSM Photodetector for Infrared Sensing Applications

A novel lateral nanocrystalline silicon (nc-Si) metal-semiconductor-metal photodetector architecture is proposed using an organic blocking layer. Fabricated devices exhibit low dark current, high dynamic range, and a measured external quantum efficiency approaching 35% at 740 nm and 15% at 850 nm. The higher performance is enabled by integrating an nc-Si film with a previously reported thin organic polyimide blocking layer and subsequently operating at high electric fields. Unlike industry standard p-i-n photodiodes, our high-performance lateral photosensor does not require doped p(+) and n(+) layers. Thus, the reported device is compatiblewith industrial standard amorphous silicon thin-film transistor display fabrication process, making it promising for large-area biometric full-hand imaging applications.