Diffusion and incorporation of Cd in solar-grade Cu(In,Ga)Se2 layers

Abstract
We examined Cd diffusion in Cu(In,Ga)Se2 layers by means of the radiotracer technique. Depth profiles of 109Cd were determined by ion-beam sputter-sectioning upon isothermal diffusion in the range from 197 to 425 °C. The Cd diffusivity can be described by the Arrhenius equation DCd = 4.8 × 10−4 exp (−1.04 eV/kBT )cm2s−1. Atom-probe tomography on a sample saturated with natural Cd at 450 °C revealed its homogeneous incorporation over the crystal volume.