Mobility-lifetime products in CuGaSe2

We report the first accurate determination of mobility-lifetime products, μτ, in thin films of a Cu-ternary chalcopyrite by photoconductivity and ambipolar diffusion length measurements. We found that for Cu-deficient, nearly intrinsic CuGaSe2 at an illumination of about 0.25 AM1 the hole’s μτ is 6×10−6 cm2/V while the electron’s μτ is 2.6×10−9 cm2/V. The lifetime dependence on the light intensity was found to be characterized by the exponent γ−1=−0.44.