Charge Collection in A-Si:H/A-Si1-XCx Multilayers Photodetectors
Amorphous semiconductors have been used as thin film transistor (TFT), solar cell, phototransistors. In this paper we study the charge collected properties of a-Si:H/a-Si1-xCx:H multilayer pin photodiode. In a-Si:H pin photodiode, the photogenerated carriers can be totally collected under strong electric field under reverse bias. However, our measurements show that in the a-Si:H/a-Si1-xCx:H multilayer pin photodiode photogenerated electrons and holes drift toward the electrodes under a certain bias, the total collected charge shows no saturation with bias and exhibits a continuous increas with reverse bias. We classify that the device works at two regions. In region I, the device behaves like a photodiode. This charge collection efficiency drop from theoretical value may indicate charge capture or confinement at the interfaces and trapping at the a-Si:H potential wells. These charges trapped or confined can be released at the interface and quantum well at higher electric field. In region II, above a critical bias voltage, the device works as a breakdown diode with a series photosensitive resistor which contributes higher collection efficiency, namely optical gain greater than unity.
T. Jing et al., "Charge Collection in A-Si:H/A-Si1-XCx Multilayers Photodetectors," Proceedings of SPIE - The International Society for Optical Engineering, SPIE -- The International Society for Optical Engineering, Jan 1994.
The definitive version is available at http://dx.doi.org/10.1117/12.190778
Second Int. Conference on Thin Film Physics and Applications
Mining and Nuclear Engineering
Article - Conference proceedings
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