Band Alignment and Interfacial Stability of Co 3 O 4 vs NiO as a Hole Transport Layer with FA 0.4 MA 0.6 PbI 3 Perovskite

作者：Xuewei Zhang, Xiaxia Cui, Qidong Tai, Daping Chu, Yuzheng Guo, John Robertson · 发表于：ACS Applied Materials & Interfaces · 年份：2025 · DOI：10.1021/acsami.4c20008 · 被引用次数：7 · 研究领域：Perovskite Materials and Applications、Chalcogenide Semiconductor Thin Films、ZnO doping and properties

High Resolution Image Download MS PowerPoint Slide The unstable cubic phase of halide perovskites (ABX 3 ) and the poor interfacial quality between their absorbing layer and the hole transport layer (HTL) cause the long-term instability of halide perovskite solar cells (PSCs). To stabilize the intrinsic cubic perovskite structure, mixing CH 3 NH + (MA + ) and CH(NH 2 ) + (FA + ) large organic ions at the A site is frequently used. Although NiO offers better stability than organic HTLs, such as poly(triaryl-amine) (PTAA), the stability of NiO-based PSCs still remains an issue, primarily due to the formation of interfacial Ni vacancies at the NiO/perovskite interface. In this theoretical study, by analyzing Co 3 O 4 /FA 0.4 MA 0.6 PbI 3 and NiO/perovskite interfaces, we show that Co 3 O 4 offers greater benefits as an HTL material than NiO for three main reasons. First, Co 3 O 4 /FA 0.4 MA 0.6 PbI 3 shows a type II band alignment with a small valence band offset (0.13 eV), whereas NiO/FA 0.4 MA 0.6 PbI 3 interfaces give type I band alignments. Second, Co 3 O 4 /FA 0.4 MA 0.6 PbI 3 interfaces show higher adhesion energy (1.48 J/m 2 ) than NiO/FA 0.4 MA 0.6 PbI 3 interfaces, indicating enhanced interfacial stability. Third, the formation of interfacial Co vacancies in NiO/FA 0.4 MA 0.6 PbI 3 presents greater difficulty due to their higher formation energy of 1.75 eV compared to the Ni vacancies in NiO/FA 0.4 MA 0.6 PbI 3, suggesting better stability under environmental conditions...