Compared with traditional RP and DJ phase two-dimensional perovskites, ACI-phase perovskite solar cells achieved relatively higher power conversion efficiency up to 19.3%, which has the different electronic structures on tuning the band gap. Herein, the electronic properties of the ACI and RP phase perovskites were systematically studied. We found that the bandgap modulation range of GA, BA and PEA perovskites all gradually decrease with increasing layer number n. Interestingly, compared with RP phase perovskites, the ACI perovskite with GA spacer cations has a smaller bandgap modulation range when the layer numbers are the same. Due to the alternative arrangement of GA and MA cations, the structure of ACI perovskite has the smallest interlayer spacing and the equatorial Pb-I-Pb angles closer to 180° Therefore, Strong anti-bonding coupling between Pb-I of ACI perovskite will increase the valence band maximum and thus decrease its band gap. The size and ligand of different spacer cations affect the physical properties of two-dimensional perovskites evidently. This theoretical investigation will offer beneficial strategies for choosing spacer cations and designing more stable perovskite devices suitable for photovoltaic applications.

与传统的 RP 和 DJ 相二维钙钛矿相比，ACI相钙钛矿太阳能电池实现了相对较高的功率转换效率，高达19.3%，在调节带隙方面具有不同的电子结构。在此，系统地研究了 ACI 和 RP 相钙钛矿的电子特性。我们发现GA、BA和PEA钙钛矿的带隙调制范围都随着层数n的增加而逐渐减小。有趣的是，与RP相钙钛矿相比，具有GA间隔阳离子的ACI钙钛矿在层数相同时具有更小的带隙调制范围。由于 GA 和 MA 阳离子的交替排列，ACI 钙钛矿的结构具有最小的层间距，赤道 Pb-I-Pb 角接近 180° 因此，ACI钙钛矿的Pb-I之间的强反键耦合将增加价带最大值，从而减小其带隙。不同间隔阳离子的大小和配体对二维钙钛矿的物理性质有明显影响。该理论研究将为选择间隔阳离子和设计更稳定的钙钛矿器件提供有益的策略光伏应用。