[9p-Z15-1~10] 13.9 Compound solar cells

△ [9p-Z15-9] The effect of Interface Band Offset of CuGaS₂ Thin Film Solar Cells

〇(M2)Myeongok Kim^1,2, Nazmul Ahsan^2,3, Zacharie Li Kao Jehl⁴, Yoshitaka Okada^1,2,3 (1.Grad. Arts and Sci. UTokyo, 2.RCAST UTokyo, 3.Elec. Eng. UTokyo, 4.IREC)

Keywords:CuGaS2 solar cell, buffer layer, band offset

To realize CuGaS₂ solar cell, there should be sufficient understanding on its appropriate solar cell structure. This research, therefore, investigates the buffer layer condition suitable for CuGaS₂ solar cell by SCAPS-1D based simulation. ZnS buffer is selected as the buffer layer of CuGaS₂ solar cell for it has wider bandgap than CuGaS₂, being transparent for light to be absorbed by CuGaS₂. When there is a positive conduction band offset about 0.4eV at CuGaS₂-ZnS interface, there are improvement in V_OC and reduction in FF. It is confirmed that the reduction in FF does not attribute to band offset at buffer-window layer interface. In recovering FF, improving the conductivity of buffer layer is found to be effective.