The hydrogenated amorphous silicon reach-through avalanche photodiodes (a-Si:H RAPDs)

Abstract

The RAPD (reach-through avalanche photodiode) structure is adopted to improve the electrical and optical performance of photosensing devices made of a-Si:H. Both the electron-injection n/sup +/ -i- delta p-i-p/sup +/ and hole-injection p/sup +/-i- delta n-i-n/sup +/ a-Si:H RAPDs are fabricated on the indium-tin-oxide-coated glass substrates by plasma-enhanced chemical vapor deposition (PECVD). The photocurrent multiplication method is employed to study the multiplication factors and the impact ionization coefficients of the RAPDs. Since the electron-injection models have better performance, the relationships between the device dimensions and characteristics, such as I-V curves, optical gains, impact ionization rates, and excess noise factors, are further studied. The results indicate that the a-Si:H RAPD is a promising device for photosensing applications.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>