Gong, XiuGuan, LiLi, QingweiLi, YanZhang, TaoPan, HanSun, QiangShen, YanGraetzel, CaroleZakeeruddin, Shaik M.Graetzel, MichaelWang, Mingkui2020-04-262020-04-262020-04-262020-04-0110.1126/sciadv.aay5661https://infoscience.epfl.ch/handle/20.500.14299/168394WOS:000525751400017Black phosphorus quantum dots (BPQDs) are proposed as effective seed-like sites to modulate the nucleation and growth of CsPbI2Br perovskite crystalline thin layers, allowing an enhanced crystallization and remarkable morphological improvement. We reveal that the lone-pair electrons of BPQDs can induce strong binding between molecules of the CsPbI2Br precursor solution and phosphorus atoms stemming from the concomitant reduction in coulombic repulsion. The four-phase transition during the annealing process yields an a-phase CsPbI2Br stabilized by BPQDs. The BPQDS/CsPbI2Br core-shell structure concomitantly reinforces a stable CsPbI2Br crystallite and suppresses the oxidation of BPQDs. Consequently, a power conversion efficiency of 15.47% can be achieved for 0.7 wt % BPQDs embedded in CsPbI2Br film-based devices, with an enhanced cell stability, under ambient conditions. Our finding is a decisive step in the exploration of crystallization and phase stability that can lead to the realization of efficient and stable inorganic perovskite solar cells.Multidisciplinary SciencesScience & Technology - Other Topicssolar-cellshalide perovskiteshybridstabilizationperformancestabilitytransportdynamicsgrowthtext::journal::journal article::research article