SIMS analysis of intentional in situ arsenic doping in CdS/CdTe solar cells

A series of CdTe/CdS devices with different tris(dimethylamino) arsine (TDMAAs) partial pressures were grown by metal organic chemical vapour deposition (MOCVD) to investigate the incorporation of arsenic into the bulk. Characterization of the growth layers using secondary ion mass spectrometry (SIMS) showed arsenic concentrations ranging from 1 x 10(16) to 1 x 10(19) atoms cm(-3). A square law dependence of arsenic concentration on the TDMAAs vapour concentration was observed. A reaction mechanism for the decomposition of TDMAAs precursor via dimerization is presented and discussed in terms of reaction kinetics.