[15a-A34-1~8] 13.10 化合物太陽電池

[15a-A34-3] 変換効率12.3%のCu₂Zn(Sn_1-xGe_x)Se₄太陽電池の特性評価

金 信浩¹、金 江玟¹、〇反保 衆志¹、柴田 肇¹、仁木 栄¹ (1.産総研)

キーワード：太陽電池、CZTGSe、ケステライト

In this study, we demonstrate new efficiency of Cu₂Zn(Sn_1-xGe_x)Se₄ (CZTGSe) thin-film solar cell. We archived new conversion efficiency of 12.3% with a very high fill factor (FF = 0.727), which is the main parameter for high conversion efficiency (Fig. 1). In addition, greatly improved open circuit voltage (V_OC) deficit (E_g/q-V_OC = 0.583 V, q: electron charge) was observed. We fitted I-V curve using single diode model to compare with our previous results, and found high FF device showed reduced diode ideality factor (A) and reverse saturation current (J₀). Improved diode parameters, V_OC deficit, A and J₀, are indicating improved junction quality and reduced recombination at the absorber/buffer interface and/or space chare region, which can be possible reason for highly improved FF.