Surface photovoltage spectroscopy on Cu(In,Ga)(S,Se) 2 /ZnS‐nanodot/In 2 S 3 systems

Single layers and combined layer systems with Cu(In,Ga)(S,Se) 2 , ZnS‐nanodot (nd) and In 2 S 3 layers were investigated by surface photovoltage spectroscopy in the Kelvin‐probe arrangement and compared with the open‐circuit voltage ( V OC ) of solar cells. The In 2 S 3 and ZnS‐nd layers were prepared by the spray ion layer gas reaction (ILGAR) technique from Indium chloride (InCl 3 ), Indium acetylacetonate (In(acac) 3 ) and Zinc acetylacetonate, respectively. The surface photovoltage signals of Cu(In,Ga)(S,Se) 2 were larger for the Cu(In,Ga)(S,Se) 2 /ZnS‐nd/In 2 S 3 than for the Cu(In,Ga)(S,Se) 2 /In 2 S 3 layer system showing that a ZnS‐nd layer additionally passivated the Cu(In,Ga)(S,Se) 2 surface. ILGAR In 2 S 3 deposition from InCl 3 precursor solution led to a modification of surface defects of ZnS‐nd and to generation of defect states below the band gap of Cu(In,Ga)(S,Se) 2 , which has not been observed for deposition from Indium acetylacetonate precursor. Defect generation during ILGAR In 2 S 3 deposition with InCl 3 precursor resulted in a lower V OC of Cu(In,Ga)(S,Se) 2 /ZnS‐nd/In 2 S 3 /ZnO : Al solar cells. Copyright © 2012 John Wiley & Sons, Ltd.