Seungyeon Hong1,Hyo Jung Kim1
Pusan National University, Department of Organic Material Science and Engineering1
Seungyeon Hong1,Hyo Jung Kim1
Pusan National University, Department of Organic Material Science and Engineering1
The metal halide perovskite materials were intensively researched for solar cells because of their outstanding photoelectronic properties. There are numerous methods to achieve high performance, high quality, and highly stable perovskite films, for example, formula combination, solution engineering, additive manufacturing, dimension control and etc. Most of those strategies pursue to obtain high-quality and well-aligned perovskite crystal structures. In this work, we adopt solvent and additive engineering and analyzed their effect on nano crystal structure of metal halide perovskite.<br/>First, we obtained high quality perovskite grains in slow crystallization process by antisolvent and the ratio of DMSO in solution in the ambient air condition at RH 20-30%. The amount and state of the intermediate phase, which is consist of PbI<sub>2</sub>-MAI-DMSO, inside the as-deposited film were analyzed from GIWAXS analysis. The deposited perovskite layer with the pure intermediate with extremely slow crystallization showed highest absorption, few grain boundaries and suppressed defect recombination losses than fast crystallized perovskite phase. Furthermore, the water resistance of perovskite film was enhanced and as a result, the long-term stability was extremely increased.<br/>And then, we employed the oleylamine(OAm) additive as defect the passivation and crystal cross-linker material. Generally, the defect the passivation and crystal cross-linker effect appeared simultaneously, and it is hard to separate the single effect of them. We could separately analyze the passivation and crystal cross-linker effect of OAm just by adopting a simple drying process during perovskite structure formation. Without the drying process, the OAm affected the orientation of the crystal structure from the surface to the bulk of the perovskite film and also exhibited the passivation effect. However, when the drying process was performed, the OAm only affected on the surface of the perovskite film. We could confirm this tendency from GIWAXS and XPS analysis.