The crystal structure and properties of organometal halide perovskites incorporating various alkali metal cations were systematically investigated. The X-ray diffraction results suggested that the lattice constant of the perovskites incorporating Li⁺, Na⁺ or K⁺ is larger than that of the perovskite without incorporation, while the incorporation of Rb⁺ or Cs⁺ did not change the lattice constant. The incorporation of Li⁺, Na⁺ or K⁺ resulted in a red shift in absorption edge, whereas the incorporation of Rb⁺ or Cs⁺ caused a blue shift. The identical trend was also found in the photoluminescence spectra, indicating the modification of the band gap by the alkali cations. The valence band maximum and conduction band minimum of the perovskites containing Li⁺, Na⁺ or K⁺ were upshifted, while those were downshifted in the Cs⁺ case. The assessments of the carrier lifetime and the defect revealed that the K⁺ containing perovskite had the least defect, followed by the perovskites containing Rb⁺, Cs⁺ and Na⁺. In addition to the barrier at the perovskite/TiO₂ interface, the defects in perovskites played a crucial role in hysteresis in the current versus voltage curves. Consequently, the efficiency of more than 20% with negligible hysteresis was achieved in K⁺ containing perovskite solar cells.

系统地研究了掺入各种碱金属阳离子的有机金属卤化物钙钛矿的晶体结构和性能。X射线衍射结果表明，掺入Li ⁺，Na ⁺或K ⁺的钙钛矿的晶格常数大于不掺入钙钛矿的钙钛矿，而Rb ⁺或Cs ⁺的掺入并未改变晶格常数。Li ⁺，Na ⁺或K ⁺的掺入导致吸收边的红移，而Rb ⁺或Cs ⁺的掺入引起了蓝色的转变。在光致发光光谱中也发现了相同的趋势，表明碱阳离子对带隙的改变。含Li ⁺，Na ⁺或K ⁺的钙钛矿的价带最大值和导带最小值上移，而在Cs ⁺情况下则降低。对载流子寿命和缺陷的评估表明，含K ⁺的钙钛矿缺陷最少，其次是含Rb ⁺，Cs ⁺和Na ⁺的钙钛矿。除了钙钛矿/ TiO ₂的阻挡层在界面上，钙钛矿中的缺陷在电流-电压曲线的滞后中起着至关重要的作用。因此，在含K ⁺的钙钛矿型太阳能电池中，磁滞可以忽略不计，效率超过20％。