Photocarrier drift measurements and solar cell models for amorphous silicon

The relationship between transport research and solar cell models for hydrogenated amorphous silicon is reviewed. It is argued that a complete program of steady-state photoconductivity, ambipolar diffusion length, and photoconductivity response time measurements is required to support modeling; the present knowledge of these measurements in electronic quality a-Si:H is summarized. A qualitative discrepancy between trap distributions used for steady-state transport models and estimated from transient photocurrent measurements is discussed.