| 초록 |
Unnatural hygroscopic property of non-hygroscopic nicotinic acid (NA) is demonstrated by tuning intermolecular distance. After adding NA into methylammonium lead iodide, (MAPbI3) NA molecules are preferentially aligned on the interface of 3-dimensional (3D) MAPbI3 crystal structure by hydrogen bond. This unique behavior allows NA to be used as a versatile additive to improve water durability of MAPbI3. After exposure under a high humidity atmosphere, (RH 100%, 35 ℃) MAPbI3 films with NA exhibited self-healing phenomena against moisture while bare MAPbI3 rapidly lost its own intrinsic property. The density functional theory (DFT) calculation was conducted to reveal how H2O molecules can effectively be absorbed by NA according to its planar molecular density. Also, further optimization of photovoltaic device performances was carried out by investigating the relationship between NA concentration and additive alignment. |
