In this study, charge extraction characteristics at the perovskite/TiO₂ interface in the conventional perovskite solar cell is studied by interface engineering. Self-assembled monolayers of phosphonic acids with different chain length and terminal functional group were used to modify mesoporous TiO₂ surface to modulate the surface property and interfacial energy barrier to investigate their effect on charge extraction and transport from the perovskite to the mp-TiO₂ and then the electrode. The chain length introduce a tunnelling distance and the end group modulate the energy level alignment at the mp-TiO₂ and perovskite interface. The work function of these SAM-modified mp-TiO₂ varied from −3.89 eV to −4.61eV, with that of the pristine mp-TiO₂ at −4.19 eV. A correlation of charge extraction and transport with respect to the modification was attempted. The study serves as a guide to engineer ETL interfaces with simple SAMs to improve the charge extraction, carrier balance and device long term stability. In this study, a maximum PCE of ∼16.09% with insignificant hysteresis was obtained, which is 17% higher than the standard device.

在这项研究中，通过界面工程研究了传统钙钛矿太阳能电池中钙钛矿/ TiO ₂界面处的电荷提取特性。使用具有不同链长和末端官能团的膦酸自组装单层膜修饰介孔TiO ₂表面以调节表面性质和界面能垒，以研究其对电荷提取和从钙钛矿到mp-TiO ₂传输的影响。然后是电极。链长引入了隧穿距离，端基调节了mp-TiO ₂和钙钛矿界面的能级排列。这些SAM改性的mp-TiO ₂的功函数变化范围为-3.89 eV至-4.61eV，原始mp-TiO _{2的变化范围}为-4.19 eV。试图将电荷提取和传输与修饰相关联。该研究可指导工程师使用简单的SAM设计ETL接口，以改善电荷提取，载流子平衡和器件长期稳定性。在这项研究中，获得的最大PCE为〜16.09％，且磁滞不明显，比标准器件高17％。