鈣鈦礦太陽能電池結晶度,形貌及化學成分之研究

Evolution of Crystallinity, Morphology, Chemical Composition of Perovskite Solar Cells

劉華鈞(Hua-Chun Liu)

指導教授 ： 陳俊維

國立臺灣大學/工學院/材料科學與工程學研究所/碩士(2014年)

https://doi.org/10.6342/NTU.2014.11096

摘要

新興吸光材料—有機無機混成鈣鈦礦 (Perovskite) 近年在太陽能電池領域逐漸嶄露頭角，極具發展性的材料特性對染敏電池，有機材料及薄膜太陽能電池研究領域造成重大影響。鈣鈦礦材料在2009年第一次引入太陽能電池應用後，迄今達到15%的光電轉換效率。眾多研究團隊對於新穎的鈣鈦礦材料富有興趣並持續進行相關結構改善及特性研究。
而根據相關研究指出，鈣鈦礦材料本身性質影響其太陽能電池表現甚鉅，由材料角度切入，可以推論材料性質會由其結晶性、化學成分及表面形貌所影響，而不同的製程參數及處理技術亦造成相異材料性質產生。
因此，本研究藉由控制不同反應前驅物濃度造成不同有機無機混成鈣鈦礦轉換反應，以探討鈣鈦礦材料結晶性質及表面形貌與其太陽能電池光電轉換效率之交互關係。我們藉由X 射線光電子能譜量測技術首次發現暫態鈣鈦礦之特徵。而後進一步分析有機材料與無機材料間在反應不完全的情況下，隨反應程度以氫鍵與凡德瓦鍵鍵結逐漸形成鈣鈦礦材料。此外，利用場發射掃描電子顯微鏡及X 射線光電子能譜縱深分析以微觀角度了解過度反應之鈣鈦礦與縱向成分分布對於鈣鈦礦太陽能電池之影響，最後提出完整鈣鈦礦反應機制。經由此研究之成果，可進一步優化鈣鈦礦太陽能電池並可望達到更高之光電轉換效率。

關鍵字

鈣鈦礦 ； 太陽能電池 ； 結晶度 ； 化學成分 ； 表面形貌

並列摘要

The recent emergence of efficient solar cells based on inorganic-organic hybrid perovskite absorbers promises to transform the fields of dye-sensitized, organic, and thin film solar cells. Since the first reports in late 2009, the inorganic–organic hybrid perovskite solar cells have achieved efficiencies of 15% so far. Interest has soared in the innovative device structures as well as new materials, promising further improvements. However, it is crucial to design the optimum device configuration and maximize solar cell efficiencies.
According to the recent researches, the photovoltaic performance is influenced by the property of perovskite significantly. In this perspective, the crystallinity, chemical composition and morphology of perovskite are considered, which in turn is dependent on the deposition techniques and subsequent treatments employed. Hence, we investigated the relation between the crystallinity, morphology and photovoltaic performance of perovskite solar cells by controlling various concentration of precursor solution. With XPS measurement, the feature of transient perovskite is first discovered in this work. Further study unravels the relation between inorganic and organic material during incomplete conversion process, which is influenced by the hydrogen bonding and Van der Waal force subsequently. In addition, SEM morphology and XPS vertical analysis are investigated subsequently to reveal the effect of excess reaction and vertical chemical composition on perovskite solar cells. The conversion mechanism of perovskite is proposed. On the basis of this research, higher power conversion efficiency is expected based on optimized perovskite solar cells.

並列關鍵字

perovskite ； solar cells ； crystallinity ； chemical composition ； morphology

參考文獻

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