本文選題：多重激子效應 + 閾值能量�。� 參考：《江西理工大學》2017年碩士論文

【摘要】：能源枯竭的危機和逐漸惡化的環(huán)境等問題,給清潔能源的發(fā)展帶來了契機。因而,太陽能的研發(fā)與利用受到了廣泛的關(guān)注。而當前太陽電池的關(guān)鍵問題是如何提高其能量轉(zhuǎn)換效率,甚至突破傳統(tǒng)單結(jié)太陽電池的理論極限。另一方面,隨著社會的電氣化發(fā)展,制備高性能的電子元器件的重要性逐漸凸顯了出來。最近在納米半導體體系中發(fā)現(xiàn)的多重激子效應為提升納米半導體太陽電池的效率和制備高性能的新一代光電器件提供了一種新方案。雖然多重激子效應從發(fā)現(xiàn)至今才只是短短的十年左右,但已經(jīng)發(fā)表了大量的研究結(jié)果。本論文詳細地綜述了多重激子效應的研究歷程、不同維度的納米半導體中多重激子的產(chǎn)生情況、實驗研究手段和理論解釋方法以及光電器件方面的應用情況,并展望了其應用前景。當前,盡管Ⅳ-Ⅵ族窄帶半導體PbS具有制備簡單、性能穩(wěn)定等特點且在遙感和環(huán)境監(jiān)測等方面有許多應用,但對納米PbS中多重激子效應的研究報道卻較少。因而,本論文較詳細地研究了PbS量子點中的多重激子效應及其對太陽電池效率的增強作用。利用多重激子效應的統(tǒng)計模型計算了納米PbS中的多重激子產(chǎn)生情況。結(jié)果表明多重激子效率I_(QE)受光子能量hv和量子點尺度d(或禁帶寬度E_g)的共同影響。I_(QE)隨光子能量hv/E_g的增加而增大,且在I_(QE)曲線上發(fā)現(xiàn)了“臺階”狀的特征——多重激子產(chǎn)生最有特征的圖譜;I_(QE)隨量子點直徑d的增加先增大后減小。納米PbS中多重激子產(chǎn)生的閾值能量Eth受其尺寸的調(diào)控,在4.00E_g到2.35E_g(t_S=50 fs)或2.50 E_g(t_S=150 fs)之間變化。利用改進的細致平衡模型探索了多重激子效應對納米PbS太陽電池效率。結(jié)果表明多重激子效應對較大尺度的PbS量子點太陽電池的極限效率u(E_g)和能量轉(zhuǎn)換效率η均有增強效果。多重激子效應可以將納米PbS太陽電池的最大效率η_(max)從49.0%提高到52.5%,其最佳尺度從d=4.4 nm(E_g=1.12 eV)增大到了11.6 nm(E_g=0.56 eV)�！袄硐搿倍嘀丶ぷ有獙⑸踔量梢詫⒆畲笮侍岣叩�84.9%。但多重激子效應對尺度較小(或E_g較大)的納米PbS半導體太陽電池轉(zhuǎn)換效率的增強效果不明顯。
[Abstract]:The crisis of energy depletion and the deteriorating environment bring opportunities to the development of clean energy. Therefore, the research and development and utilization of solar energy have received extensive attention. At present, the key problem of solar cells is how to improve their energy conversion efficiency and even break through the theoretical limits of traditional single-junction solar cells. On the other hand, with the development of electrification, the importance of preparing high-performance electronic components is becoming more and more important. The multiple exciton effect found recently in nanoscale semiconductor systems provides a new scheme for improving the efficiency of semiconductor solar cells and preparing a new generation of optoelectronic devices with high performance. Although the multiple exciton effect has only been discovered for only about ten years, a large number of studies have been published. In this paper, the research history of multiexciton effect, the generation of multiple excitons in different dimensions of nanoscale semiconductors, the experimental research methods and theoretical explanation methods, and the applications of optoelectronic devices are reviewed in detail. The prospect of its application is also prospected. At present, although 鈪，

本文編號：1918069