体相异质结钙钛矿太阳电池的稳定性

Preparation and Stability of Bulk Heterojunction Perovskite Solar Cells

钙钛矿太阳电池的光电转换效率取得了硅太阳电池的水平,然而制约其产业化发展的主要瓶颈是稳定性。为探索其衰减的物理规律,使用新两步连续沉积方法成功的制备了体相异质结钙钛矿太阳电池,其光电转换效率为6.73%。这种方法解决了传统两步法钙钛矿薄膜不均匀和相互扩散两步法反应不完全的缺点。将体相异质结钙钛矿太阳电池放在空气中10、20和80 min时对其稳定性进行测试,发现其光电转换效率会逐渐降低,它的开路电压几乎不变,它的短路电流密度和填充因子逐渐减小。通过交流阻抗测试进一步证实其衰减的主要原因是钙钛矿太阳电池的复合电阻和载流子寿命不断减小。主要原因可能钙钛矿材料在晶界处吸收空气中的水分和氧气,导致其分解。

The photoelectric conversion efficiency(PCE)of perovskite solar cells(PSCs)has reached the level of silicon solar cells,but the main bottleneck restricting its industrialization development is stability.In order to explore the physical law of its attenuation,bulk heterojunction PSCS were successfully fabricated by a new two-step continuous deposition method,and the PCE was 6.73%.This method overcomes the shortcomings of the traditional two-step method,such as the inhomogeneity of perovskite films and the incomplete reaction for the two-step method.The stability of bulk heterojunction PSCs is tested when they are exposed to air for 10,20 and 80 min.It is found that the PCE of bulk heterojunction PSCs decreases gradually,the open circuit voltage of bulk heterojunction PSCs is almost constant,and the short circuit current density and filling factor of bulk heterojunction PSCs decrease gradually.Through the AC impedance test,it is further confirmed that the main reason for the attenuation is the decreasing composite resistance and carrier lifetime for PSCs.The main reason may be that perovskite materials absorb water and oxygen in the air at the grain boundary,leading to its decomposition.