A high stability, hole-conductor-free mixed organic cation pervoskite solar cells based on carbon counter electrode

In this work, hole-conductor-free mixed organic cation perovskite solar cells based on carbon counter electrode were fabricated under air atmosphere with high humidity condition around 50%. The photovoltaic performance of the perovskite solar cells with mixed organic cation perovskite (FA)x(MA)1−xPbI3 by chemical modification the molar ratios x were demonstrated. The light harvesting abilities and crystal morphology could be controlled with x from 0 to 0.4 which resulted in a corresponding diversification of photoelectric properties in perovskite solar cells. Electrical impedance measurements were performed for investigating the electron transport issues in perovskite solar cells with various x. The optimized perovskite solar cells delivered a short-circuit photocurrent density of 21.63 mA/cm3, open-circuit voltage of 980 mV, fill factor of 0.45 and overall conversion efficiency of 9.53% as x = 0.3. The long-term stability of the optimized perovskite solar cells was exhibited and the overall conversion efficiency retained about 91% after 49 days in air with humidity around 50%. The hole-conductor-free perovskite solar cells based on carbon counter electrode have low-cost and bring a prosperous application foreground in the future photovoltaic community.