Abstract
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 increase 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.
Original language | English |
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Pages (from-to) | 345-350 |
Number of pages | 6 |
Journal | Proceedings of SPIE - The International Society for Optical Engineering |
Volume | 2364 |
DOIs | |
State | Published - 26 Oct 1994 |
Event | 2nd International Conference on Thin Film Physics and Applications 1994 - Shanghai, China Duration: 15 Apr 1994 → 17 Apr 1994 |
Keywords
- Amorphous silicon
- Charge collection
- Multilayers
- Photodiode