The performance of CuInSe2 monograin layer solar cells with variable indium content

The recent results on the characterization of CuInSe2 monograin layer solar cells are presented. The influence of different Cu/In ratio on solar cell characteristics was studied. It was determined that device-quality CuInSe2 monograin powder could be grown from CuIn precursor alloys with a composition between 0.9 < Cu/In < 1. For absorber material, these powders were post-treated in sulphur vapour. The cells based on these absorbers showed efficiencies up to 9.5%. However, the quantum efficiency measurements revealed a significant loss in the long-wavelength range of photons λ > 800 nm. The derivative of QE with respect to wavelength showed two peaks at the energy values of ∼ 1.4 eV and ∼ 1.03 eV, which proves that these sulphurised absorber materials consist of two different phases.