A three-path model for visible/near infrared μc-Si:H p–i–n detectors

Abstract

The photocurrent delivered by entirely microcrystalline p–i–n-Si:H detector is analyzed under different applied bias and light illumination conditions. The internal collection depends not only on the energy range but also on the illumination side. Under 〈p〉 and 〈n〉 side irradiation the internal collection properties have an atypical shape. It is larger for an applied bias less than the open circuit voltage, has a decrease near the open circuit voltage (higher under 〈n〉 side illumination) and becomes almost invariant for larger voltages. Additionally, numerical modeling of the visible/near infrared detector including the grain boundaries and the interfaces complements the study and provides a knowledge into the internal physical process.