本文選題：鈣鈦礦太陽能電池 + 退火溫度��； 參考：《中國(guó)科學(xué)技術(shù)大學(xué)》2017年博士論文

【摘要】：近年來,鈣鈦礦太陽能電池由于制備工藝簡(jiǎn)單、成本低廉、可制備柔性器件且光伏性能高達(dá)22.1%等優(yōu)勢(shì),吸引了人們的關(guān)注和研究。高效率的太陽能電池不僅依賴鈣鈦礦薄膜的質(zhì)量和性質(zhì),而且取決于接觸層的性質(zhì)和能帶結(jié)構(gòu)。一方面,鈣鈦礦材料具有高的載流子遷移率、長(zhǎng)的擴(kuò)散系數(shù)、大的光學(xué)吸收系數(shù)和可調(diào)控的光學(xué)帶隙等優(yōu)越的性質(zhì),因而可以作為電池的光吸收層去實(shí)現(xiàn)載流子的產(chǎn)生、輸運(yùn)和分離。同時(shí),鈣鈦礦薄膜的質(zhì)量直接影響到電池的光伏性能。人們開發(fā)各種方法去實(shí)現(xiàn)高質(zhì)量的鈣鈦礦薄膜,從而有效地減小載流子的復(fù)合和提高電池的性能,已是研究的熱點(diǎn)之一;另一方面,與鈣鈦礦層相鄰的接觸層,其本身必須具備良好的光學(xué)、電學(xué)性能和恰當(dāng)?shù)哪芗?jí)位置,才能實(shí)現(xiàn)電荷載流子在界面有效的抽取和傳輸。本論文主要集中在兩個(gè)方面開展:一是從鈣鈦礦薄膜的制備工藝入手,通過優(yōu)化制備條件,獲得高質(zhì)量的薄膜,從而提高電池的光電轉(zhuǎn)化效率;二是通過探索影響界面電荷抽取的關(guān)鍵因素,進(jìn)一步提升電荷傳輸性能。具體的研究?jī)?nèi)容如下:在鈣鈦礦材料的制備過程中,退火溫度極易影響溶劑的蒸發(fā)和薄膜的形核生長(zhǎng),從而改變薄膜表面的形貌。因此,研究退火溫度對(duì)鈣鈦礦薄膜的影響,有利于優(yōu)化電池的光伏性能。采用兩步沉積技術(shù)制備CH_3NH_3PbI_3鈣鈦礦薄膜,揭示了退火溫度和光學(xué)吸收強(qiáng)度,薄膜表面的晶粒尺寸及結(jié)晶性之間的依賴關(guān)系。實(shí)驗(yàn)結(jié)果表明,CH_3NH_3PbI_3薄膜表面的晶粒尺寸隨著退火溫度的升高而單調(diào)增加;當(dāng)退火溫度高于120 ℃℃,有碘化鉛的出現(xiàn)且隨著退火溫度的增加,其含量進(jìn)一步增大;CH_3NH_3PbI_3薄膜的光學(xué)吸收強(qiáng)度和電池的光伏效率隨著退火溫度的增加,先增大后減小,并在退火溫度為120℃℃時(shí)同時(shí)獲得了最優(yōu)值。此外,通過優(yōu)化兩步沉積過程中的退火溫度,鈣鈦礦太陽能電池的最優(yōu)和平均光電轉(zhuǎn)化效率分別達(dá)到了 17.61%和16.40%。這些結(jié)果證明了溫度在鈣鈦礦薄膜制備中扮演至關(guān)重要的作用,同時(shí),提供了一種優(yōu)化電池效率的重要途徑。鈣鈦礦太陽能電池的光伏性能依賴于薄膜之間的界面,因此,通過有效的界面能帶處理,不僅有利于提高電池的電荷傳輸效率,還可以深入理解電荷轉(zhuǎn)移的機(jī)理。通過在ZnO薄膜制備過程中加入不同含量的Sn(0≤x≤0.2),調(diào)控鈣鈦礦太陽能電池中ZnO電子傳輸層的能帶結(jié)構(gòu)的變化。研究發(fā)現(xiàn),Zn1-xSnxO薄膜表面形貌和結(jié)晶性并無明顯的變化;在0≤x≤0.2范圍內(nèi),隨著Sn含量的增加Zn1-xSnxO的功函數(shù)和光學(xué)帶隙均出現(xiàn)V-型變化的趨勢(shì);Sn的摻雜調(diào)控鈣鈦礦太陽能電池的光伏性能,例如,光電轉(zhuǎn)化效率、開路電壓、短路電流和填充因子均出現(xiàn)V-型的變化。通過控制Sn的摻雜含量(0≤x≤0.2),獲得了電池最優(yōu)的光伏性能:光電轉(zhuǎn)化效率為16.47%、開路電壓為1.04 V、短路電流24.13 mAcm~(-2)和填充因子為65.62。
[Abstract]:In recent years, perovskite solar cells have attracted much attention due to their advantages of simple preparation process, low cost, flexible devices and photovoltaic performance of up to 22.1%. High efficiency solar cells not only depend on the quality and properties of perovskite films, but also depend on the contact layer properties and band structure. On the one hand, perovskite has the advantages of high carrier mobility, long diffusion coefficient, large optical absorption coefficient and adjustable optical band gap, so it can be used as the photoabsorption layer of the battery to realize the generation of carriers. Transport and separation At the same time, the quality of perovskite film directly affects the photovoltaic performance of the cell. People develop various methods to realize high quality perovskite films, thus effectively reducing carrier recombination and improving the performance of the battery, on the other hand, the contact layer adjacent to the perovskite layer, In order to realize the effective extraction and transmission of charge carriers at the interface, it is necessary to have good optical and electrical properties and appropriate energy level positions. This paper mainly focuses on two aspects: first, from the preparation process of perovskite film, through the optimization of preparation conditions to obtain high-quality thin films, thereby improving the photovoltaic conversion efficiency of the battery; The other is to further improve the charge transport performance by exploring the key factors that affect the interface charge extraction. The main contents are as follows: during the preparation of perovskite, the annealing temperature can easily affect the evaporation of solvent and the nucleation and growth of the film, thus changing the surface morphology of the film. Therefore, studying the effect of annealing temperature on perovskite film is beneficial to optimize the photovoltaic performance of the cell. CH_3NH_3PbI_3 perovskite thin films were prepared by two-step deposition technique. The dependence of annealing temperature, optical absorption intensity, grain size and crystallinity on the surface of the films was revealed. The experimental results show that the grain size on the surface of CH3NH3PbI3 thin film increases monotonously with the increase of annealing temperature, and when the annealing temperature is higher than 120 鈩，

本文編號(hào)：1973860