Recently, silicon-based solar cell research group leaded by LIU Shengzhong professor of Dalian National Laboratory for Clean Energy Lab, has developed a facile but fast growth method to prepare large single crystalline perovskite CH3NH3PbI3 up to >2 inches. To the best of our knowledge, this is the first time to report the perovskite with crystal dimension exceeded half inch. The related results were published online in the journal of advanced materials (Adv. Mater. 2015, 27 (35), 5176-5183. doi:10.1002/adma.201502597).The Advanced Materials editor gave the article highly evaluation and wrote a highlight comments, and the comment has been published online at the MaterialViews web site (http://www.materialsviews.com/supersize-single-crystalline-perovskite-crystals-adma-201502597/).
Semiconductor materials with a perfectly aligned lattice structure offer the best performance, not only in integrated circuits but also in photovoltaics and opto- electronics, etc. It is the invention of growth techniques for large-sized single crystals that has led to the birth of modern electronics, solar cells, solid-state lasers, light emitting diodes (LEDs), and so on. The organic–inorganic hybrid perovskite CH3NH3PbX3 (X =Cl, Br, I) has emerged as a strong competitor in photovoltaic and general optoelectronic applications due to its superior characteristics including high absorption coefficient, direct band gap, long carrier life time, and high balanced hole and electron mobility, etc. In fact, the National Renewable Energy Laboratory (NREL) certificated power conversion efficiency for the perovskite solar cell has reached 20.1%. However, until now, all perovskite solar cells have been based on microcrystalline and amorphous components, limited by the unavailability of large, single-crystalline material. As there are plenty of grains, boundaries, voids, and surface defects within the perovskite material, it is expected that significant efficiency losses will be seen, caused by these recombination sites. So the research team developed a facial but fast growth method to prepare large single crystalline perovskite CH3NH3PbI3 up to more than 100 mm. The powder XRD analyses confirrm the formation at room temperature. Optical-absorption measurements reveal that all three perovskite crystals show broader absorption, compared to their microcrystalline counterparts. In addition, we have observed the PL emission at 402 nm from CH3NH3PbCl3 for the first time. Both the TGA and the DSC show that the large CH3NH3PbCl3 crystals are more stable at much higher temperature compared to their thin-film material counterpart. The low trap density and high carrier mobility indicate that the present large, single-crystalline CH3NH3PbX3 (X = Cl, Br, I) is a promising material for high performance optoelectronic devices.
This work acknowledge support from the National University Research Fund (GK261001009), the Chang jiang Scholar and Innovative Research Team(IRT_14R33), the 111Project (B14041).(Article /Figure Doudou Zhang)