Spectroradiometric diagnostics of amorphous silicon solar cells

The effect of bias irradiance (1 μWm-2 ≤ Eb ≤ 1 kWm-2) on spectral responsivity s(λ) and diffusion length Leff is studied by using a dufferential spectral responsivity method. Various types of a-Si solar cells show quite different photoinduced effects: reversible and non-reversible sublinear and/or superlinear behaviour befween photocurrent density isc and irradiance E. In the variation of spectral responsivity and diffusion length as function of irradiance/photocurrent no specific dependence but some systematic features have been found where non reversible change of responsivity is preferentially observed at low bias irradiance