Yang Jiandong, Wang Jun, Yang Wenshu, Zhu Ying, Feng Shuang, Su Pengyu, Fu Wuyou
State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China.
School of Physics and Optoelectronic Engineering, Shandong University of Technology, Zibo 255000, China.
Nanomaterials (Basel). 2022 Oct 18;12(20):3653. doi: 10.3390/nano12203653.
The scaffold layer plays an important role in transporting electrons and preventing carrier recombination in mesoporous perovskite solar cells (PSCs), so the engineering of the interface between the scaffold layer and the light absorption layer has attracted widespread concern. In this work, vertically grown TiO nanorods (NRs) as scaffold layers are fabricated and further treated with TiCl aqueous solution. It can be found that a thin brookite TiO nanoparticle (NP) layer is formed by the chemical bath deposition (CBD) method on the surface of every rutile NR with a low annealing temperature (150 °C), which is beneficial for the infiltration and growth of perovskite. The PSC based on the TiO NR/brookite NP structure shows the best power conversion of 15.2%, which is 56.37% higher than that of the PSC based on bare NRs (9.72%). This complex structure presents an improved pore filling fraction and better carrier transport capability with less trap-assisted carrier recombination. In addition, low-annealing-temperature-formed brookite NPs possess a more suitable edge potential for electrons to transport from the perovskite layer to the electron collection layer when compared with high-annealing-temperature-formed anatase NPs. The brookite phase TiO fabricated at a low temperature presents great potential for flexible PSCs.
支架层在介孔钙钛矿太阳能电池（PSC）中对电子传输和防止载流子复合起着重要作用，因此支架层与光吸收层之间界面的工程设计受到了广泛关注。在这项工作中，制备了垂直生长的TiO纳米棒（NRs）作为支架层，并用TiCl水溶液进一步处理。可以发现，通过化学浴沉积（CBD）方法在每个金红石NR表面以低退火温度（150°C）形成了一层薄的板钛矿TiO纳米颗粒（NP）层，这有利于钙钛矿的渗透和生长。基于TiO NR/板钛矿NP结构的PSC显示出最佳功率转换率为15.2%，比基于裸NRs的PSC（9.72%）高出56.37%。这种复杂结构具有更高的孔隙填充率和更好的载流子传输能力，同时陷阱辅助载流子复合较少。此外，与高退火温度形成的锐钛矿NP相比，低退火温度形成的板钛矿NP具有更适合电子从钙钛矿层传输到电子收集层的边缘电位。低温制备的板钛矿相TiO在柔性PSC中具有巨大潜力。
