Study of a new indium sulphide derivative for buffer layer application

Thin films of /spl beta/-In/sub 2/NaS/sub 3/ (BINS) have been synthesized by physical vapour deposition (PVD). The determination of their properties has shown that the films have an n-type electrical conductivity around 10/sup -6/ S.cm/sup -1/ and their optical band gap increases from 2.10 eV to 2.95 eV. These properties make the wide band gap BINS thin films potential candidates to substitute CBD-CdS in thin films CIGS-based solar cells. The first CIGS/BINS cell has reached efficiency higher than 8%, with a V/sub oc/ of 660 mV.