| 초록 |
We applied solvents with different donor number of Gutmann as additives to improve the limited solubility of 2-Methoxyethanol(2ME) in perovskite. In DMF based solution, high donor number solvents dissolve Lewis acid well, but the additives strongly interacted with the precursor to form an insoluble adduct in 2ME-based solution. As a result, solution processing was impossible with high donnor number solvents. However, we found that N-Methyl-2-pyrrolidone(NMP) with a relatively low donor number did not induce precipitation in the 0.6M precursor solution. When 40 mol% NMP was added, a plan perovskite film was formed without pin-holes. The device made with this perovskite film had enhanced device performance(18.85%) in comparison with pristine 2ME based device(11.58%). |
