Fig. 6From: Enhanced Power Conversion Efficiency of Perovskite Solar Cells with an Up-Conversion Material of Er3+-Yb3+-Li+ Tri-doped TiO2a PCE dependence of solar cells on the content of UC-TiO2 (UC-TiO2: 30NR-D = x:100, v/v) in the mixture. b I-V curves of the best performance devices without UC-TiO2 and with UC-TiO2Back to article page