Influence of AGS Layer Insertion at Absorber/ITO Interface on Structural and Photovoltaic Properties of Ultrathin Cu(In,Ga)Se2 Solar Cells

The insertion of a sulfurized-AgGa (AGS) layer at Cu(In,Ga)Se2 (CIGSe)/ITO interface was found effective in improving the PV properties of ~300 nm thick CIGSe ($\mathrm{E}_{\mathrm{g}}\approx 1.5$ eV)absorber-based solar cells (deposition time $(\mathrm{t}_{\mathrm{dep}})=90$ min, substrate temperature $(\mathrm{T}_{\mathrm{s}})=490$ °C) [1]. This study explores the benefits of the AGS layer when $\mathrm{T}_{\mathrm{s}}$ and $\mathrm{t}_{\mathrm{dep}}$ for the CIGSe deposition are 560°C and 15 min, respectively. The PV properties of a CIGSe solar cell modified with the AGS layer are relatively poor when $\mathrm{T}_{\mathrm{s}}$ is high and tdep is short.