As promising photo-absorbing materials for photovoltaics, organic-inorganic hybrid perovskite materials such as methylammonium lead iodide and formamidinium lead iodide, have attracted lots of attention from many researchers. Among the various factors to be considered for high power conversion efficiency (PCE) in perovskite solar cells (PSCs), increasing the grain size of perovskite is most important. However, it is difficult to obtain a highly crystalline perovskite film with large grain size by using the conventional hot-plate annealing method because heat is transferred unidirectionally from the bottom to the top. In this work, we presented radiative thermal annealing (RTA) to improve the structural and electrical properties of perovskite films. Owing to the omnidirectional heat transfer, swift and uniform nuclei formation was possible within the perovskite film. An average grain size of 500 nm was obtained, which is 5 times larger than that of the perovskite film annealed on a hot-plate. This perovskite film led to an enhancement of photovoltaic performance of PSCs. Both short-circuit current density and PCE of the PSCs prepared by RTA were improved by 10%, compared to those of PSCs prepared by hot-plate annealing.
Bibliographical noteFunding Information:
This work was supported by the Pioneer Research Center Program (NRF-2016M3C1A3908893, NRF-2014M3C1A3016468) and by the Basic Science Research Program (NRF-2016R1A2B4006395) through the National Research Foundation of Korea (NRF) funded by the Ministry of Education. G. Y. Jung was partially supported by the GIST Research Institute (GRI) project through a grant provided by GIST in 2018. C.-L. Lee thanks the National Research Foundation of Korea (NRF) for nancial support through a grant funded by the Korean government (MSIP; NRF-2016R1A2B4013003 and NRF-2018R1A2A3075144) and a grant funded by GIST 2019 (Research on Advanced Optical Science and Technology).
© 2019 The Royal Society of Chemistry.
ASJC Scopus subject areas
- Chemical Engineering(all)