Radiotracer diffusion of Ag in Cu(In,Ga)Se2 thin films

Wegner M., Wilangowski F., Wuerz R., Stolwijk N.

Abstract

Diffusion of Ag in Cu(In,Ga)Se2 was investigated utilizing radiotracer sputter-profiling of 110mAg. After removal of the CdS capping layer the 110mAg isotope was deposited on the front-surface of the Cu(In,Ga)Se2 layer and the samples were subjected to isothermal annealing in a temperature interval ranging from 573 K up to 648 K. The observed Ag diffusivity can be described by the following Arrhenius equation D(T) = 0.12 exp(-1.29 eV/kBT) cm2/s. Comparison with the diffusivities of Zn, Cd and Fe in Cu(In,Ga)Se2 in the investigated temperature regime reveals similiar activation energies, but a larger pre-exponential factor for Ag diffusion resulting in accelerated diffusion kinetics.