Wavelength-dependent J–V characteristics of CuIn1-x Ga x (S,Se)2 solar cells and carrier recombination.

We propose here a new experimental setup, allowing the probing of CuIn_1-xGa_x(S,Se)₂ (CIGSSe) solar cells under varying wavelengths and intensities, using a supercontinuum laser. The setup is used to study the effects of potassium treatment on CIGSSe cells. Their J–V characteristics are taken at 500 nm and 950 nm, at intensities from 5 × 10¹⁴ photons cm⁻² s⁻¹ to 4 × 10¹⁶ photons cm⁻² s⁻¹. The untreated sample’s response shows strong dependence on the exciting wavelength. After potassium treatment, this dependence is a lot less important. Using simulation, we show that this difference can be explained by a reduction in the defect density in the depletion region. [ABSTRACT FROM AUTHOR]