An unnatural hygroscopic property of nonhygroscopic nicotinic acid (NA) is demonstrated by tuning the intermolecular distance. After addition of NA into methylammonium lead iodide, (MAPbI3) NA molecules are preferentially aligned on the interface of the three-dimensional (3D) MAPbI3 crystal structure by a hydrogen bond. This unique behavior allows NA to be used as a versatile additive to improve the water durability of MAPbI3. After exposure under a high humidity atmosphere (RH 100%, 35 °C), MAPbI3 films with NA exhibited self-healing phenomena against moisture while bare MAPbI3 rapidly lost its own intrinsic property. Density functional theory (DFT) calculations were 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.
Bibliographical noteFunding Information:
D.H.C. and Y.S. contributed equally to this work. J.H.P. acknowledges the support from the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (2018M1A3A3A02065974, 2019R1A2C3010479, 2021M3E6A1015823). D. H. C. was supported by National Research Foundation of Korea (NRF) Grant funded by the Korean Government (NRF-2018-Global Ph.D. Fellowship Program, 2018H1A2A1063511).
© 2021 American Chemical Society.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Physical and Theoretical Chemistry