| 摘要: | 近年鈣鈦礦太陽能電池發展廣泛且快速，為走向商業化，本研究以相較傳統旋轉塗佈製程更適合放大面積製造的刮刀塗佈製程為主題，探討前驅液選擇、刮刀塗佈溫度與混合溶劑比例於此製程中塗佈鈣鈦礦薄膜的影響。實驗結果發現，不同單一或混合溶劑對膜厚與薄膜的連續性有明顯差異，過薄或不連續薄膜會造成主動層吸光率不佳，影響元件之短路電流表現。塗佈溫度則是影響薄膜粗糙度的關鍵，過低的塗佈溫度會使刮刀經過後溶劑持續因表面張力流動，造成分布不均勻的薄膜表面形貌；過高的塗佈溫度則會使溶劑快速揮發，使薄膜表面出現少量破洞，降低其覆蓋率。塗佈溫度亦主導鈣鈦礦成膜時結晶相態的變化則可由文獻得到印證，越高的塗佈溫度，其前驅液直接結晶成為規則排列的鈣鈦礦，不易生成不穩定的溶劑化合物中間相與碘化鉛相，可得更佳的薄膜品質。而深入探討GBL與DMSO混合溶劑比例可發現，DMSO所佔比例越多的薄膜其結晶較大較平整，應用於電池元件之轉換效率表現較佳；反之，GBL所占比例越多的薄膜，因其結晶核密度大，使結晶尺寸受到限制，且由於GBL溶劑特性造成的薄膜表面易於溶劑揮發過程產生中心向外圍的熱對流，形成如盆地狀的表面形貌，造成薄膜粗糙與缺陷現象。本研究由上述三個方向優化之條件，分析出最佳塗佈溫度130℃與最佳溶劑比例GBL:DMSO=1:9(v:v)，製作n-i-p結構與p-i-n結構太陽能電池，分別得到12.16%、13.19%之光電轉換效率，更由效率分布比較其薄膜均勻性，進而應用於放大面積約120倍之p-i-n結構太陽能次模組，得到11.13%之效率。刮刀塗佈法製程簡單、材料有效運用、元件有效面積無限制等優點，於大規模製造鈣鈦礦太陽能電池具有相當的競爭力。;In recent year, perovskite solar cells has developed widely and quickly. In order to commercialize, we use blade-coating method which is more easily to up-scale than the most commonly used spin-coating process to investigate the effect of the precursor solvent, coating temperature, and the ratio of the mixed solvent. We find that there is obvious difference in film thickness and continuity when used distinct single or mixed solvent. The bad absorption of the active layer attributed to the discontinuous film or when the film is too thin, which caused the low device short circuit current. Coating temperature is the key of the roughness of the film. The solvent will keep flowing because of the surface tension after the blade go through when in lower coating temperature, which lead to the uneven morphology. In contrast, when it comes to higher coating temperature, the solvent volatilize so quick that bring about the holes on the film surface, result the lower coverage. Coating temperature is also the main role of the phase change when forming the perovskite crystalline. The precursor react directly into the ordered perovskite crystal at higher coating temperature, the unstable solvate and intermediate are found less. Furthermore, we discuss the film quality of the different solvent ratio of GBL and DMSO. The more DMSO, the larger the crystalline, and also get the better power conversion efficiency when applied to the solar cells. On the contrary, the more GBL, the bigger the density of the nucleus, cause the limited grain size. Due to the characteristic of the solvent GBL, the film is easily form the ring-like surface when the solvent volatilize and emerge the center-to-outer heat convection, which is the reason why the roughness and defects. This study is the analyzation about the above three optimization and got the best coating temperature 130℃ and the best ratio of the solvent GBL: DMSO=1:9(v: v), the n-i-p and p-i-n type solar cells respectively yield 12.16% and 13.19%. After enlarge the active area about 120 times as p-i-n type module with the efficiency of 11.13%. The advantages such as easy-made, material used effectively, and no active area limitation, blade-coating is a very promising process for up-scale manufacture. |
