在新世代的綠色科技中，以金屬滷化物合成的鈣鈦礦材料和有機無機材料來製備太陽能電池是最具有前景性和發展性的項目之一。這代表我們能通過材料設計，元件工程和理論機制三者來進行太陽能電池功率轉換效率的提升。因此(1) 如何藉由多樣化的材料來擴大或補足太陽光的吸收波段，以及(2) 如何改善彼此材料之間的接面情況和(3) 如何找到適合的元件結構，是目前太陽能電池領域所關注的主題。而太陽能電池的結構從一開始最簡單的單層和塊材，逐漸演變成現今最普遍且最有效果，並作為電子施體與電子受體的雙層結構。然而，在利用有機材料作為雙層結構中薄膜的情況下，因其自身狹窄的有機半導體吸收能帶，使其本身只能吸收部份的太陽能光譜且同時進一步限制元件在光電轉換效率的改善。本論文主要探討如何利用多個具有互補吸收光譜的材料，以層層堆疊的方式製備雙層和三元太陽能電池，並藉此提高元件的光電轉換效率。我們研究了雙層結構與三元結構二者中激子如何分離、電荷傳輸的情況和薄膜形貌的影響等。結果顯示，我們通過將不同的材料，如：共軛聚合物、小分子材料和量子點材料，以同時或個別的方式加入至雙層或三元的結構之中，使得太陽能電池的主要參數，如：開路電壓、短路電流密度、填充因子和光電轉換效率等，都有明顯的改善。
本研究以雙層和三元作為元件結構，針對有機太陽能電池(Organic solar cells, OSCs)和金屬滷化物鈣鈦礦太陽能電池(CH3NH3PbI3, Perovskite solar cells, PSCs)二者的機制進行了詳細的研究；而OSCs和PSCs將會分別於第三章和第四章進行討論。於第三章第一節我們將利用α六噻吩(α-sexithiophene, α-6T)、硼亞酞菁氯化物(Boron subphthalocyanine chloride, SubPc)和2-硼, 3-萘酞菁硼(Boron sub-2, 3-naphthalocyanine chloride, SubNc)作為電子施體和受體材料，探討OSCs元件於雙層結構下主動層厚度變化所帶來的影響，並進一步討論激子分離和電荷傳輸的機制情況。於第三章第二節則是將前述所用的三種材料，探討於三元結構下元件主動層厚度變化所帶來的影響。同時針對三種基本不同的機制：(1) 電荷轉移、(2) 能量轉移和(3) 平行聯動進行深入的研究。於第三章第三節，我們將以氧化鉬(Molybdenum Trioxide, MoO3)和高導電高分子聚合物材料：聚二氧乙基噻吩-聚苯乙烯磺酸(Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), PEDOT:PSS)作為電洞傳輸層，於不同主動層之OSCs的傳導機制和PCE變化進行分析研究。利用吸收光譜和X射線光電子能譜來檢測MoO3和酞菁銅(Copper phthalocyanine, CuPc)之間的相互作用。發現到MoO3和CuPc之間的電子轉移，引起界面態的形成在MoO3/CuPc界面，導致費米能階在界面處的釘扎。因此以CuPc為主動層之元件Voc無法藉由插入MoO3陽極緩衝層而有所改善。第三章第四節為探討OSCs在有無富勒烯作為單一或雙層電子受體之下，至使雙層和三元結構元件在光電特性上的差異性。
本論文第四章第一節為使用各種不同溶劑製造CH3NH3PbI3 PSCs對效率之影響進行研究。該元件結構是由銦錫氧化物(ITO)/聚二氧乙基噻吩:聚苯乙烯磺酸(PEDOT：PSS)/CH3NH3PbI3(使用各種溶劑製造)/C60/浴銅靈(Bathocuproine, BCP)/Ag。使用的溶劑有二甲基甲醯胺(Dimethylformamide, DMF)，γ丁內酯(γ-butyrolactone, GBL)，二甲基亞碸(Dimethyl sulfoxide, DMSO)，DMSO和DMF混合(1:1體積/體積)，和DMSO和GBL混合(1:1體積/體積)。結果顯示出使用DMSO中的混合溶劑可得到9.77％的轉換效率。最佳的混合溶劑為DMSO：DMF：GBL（5：2：3體積/體積/體積），可使得鈣鈦礦太陽能電池轉換效率進一步提高到10.84％。本論文第四章第二節為使用不同溫度退火處理和各種材料作為受體的CH3NH3PbI3 PSCs進行了研究。該元件結構是由ITO/PEDOT:PSS/CH3NH3PbI3(不同溫度退火處理)/受體材料/BCP/Ag結構。CH3NH3PbI3層的熱退火處理為從60℃至120℃進行。結果顯示出退火處理的溫度對元件的PCE有顯著影響。此外，在該元件中使用的受體材料分別為C60，C70和3,4,9,10-苝雙苯並咪唑。結果顯示出PSCs的發電機制與OSCs是相近的，都是利用供體/受體界面去解離束縛在一起的電子電洞對而產生光伏效應，最後元件效率可達到11.58%。

In the novel generation of green technology, the synthesis of metal halide and organic-inorganic materials is one of the most promising and developing items to fabricate the solar cells because we can improve the power conversion efficiency (PCE) of solar cells through material design, device engineering and theoretical mechanism. At present, there are three important topic of current optoelectronics device, including (1) how to broaden or enhance the absorption band of the sun light via versatile materials, (2) how to optimize the interface between each used materials and (3) how to find the appropriate device structure. However, from the beginning named single and bulk heterojunction to the currently common and effective binary components, the bilayer structure which is made of electron donor and electron acceptor has become main device. In the case of using the organic material as thin film in the bilayer device, binary active layers can only utilize a part of the solar spectrum in thin films, which limits the further efficiency improvements because the absorption bands of organic semiconductors are intrinsically narrow. This study mainly explores how to utilizing multiple components with complementary absorption bands to fabricate bilayer and ternary solar cells and improve the PCE of device. We also studied other important roles, such as facilitating exciton dissociation and charge transport and optimizing the film morphology. As a result, the main parameters of OSCs, including the open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF) and PCE, can be individually or simultaneously enhanced by incorporating different third components into different binary systems, such as conjugated polymers, small molecules, and quantum dots.
In this dissertation, the influence of different factors on the performance of organic solar cells (OSCs) and CH3NH3PbI3 perovskite solar cells (PSCs) is investigated in detail. The OSCs are studied and discussed in Chapter 3, and the PSCs are investigated and discussed in Chapter 4. The section 1 in Chapter 3 is focused on the effect of the change for active layer in the bilayer structure on the OSCs based onα-sexithiophene (α-6T), Boron subphthalocyanine chloride (SubPc) and Boron sub-2, 3-naphthalocyanine chloride (SubNc) as the electron donor and electron acceptor. And the further discussion of exciton dissociation and charge transport has been accomplished simultaneously. The section 2 in Chapter 3 is focused on the effect of the change for active layer in the bilayer structure on the OSCs based on the above investigation and results, attributing to three fundamentally different mechanisms in ternary OSCs: charge transfer, energy transfer, and parallel-linkage. The section 3 in Chapter 3 is focused on the research of hole transport layer in the different active layer of device based on the molybdenum trioxide (MoO3) and the poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). Results show a great enhancement of the open-circuit voltage in the device. This enhancement originates from the work function improvement of indium tin oxide (ITO) by covering the MoO3 layer. However, the function of MoO3 is not evident in the device that uses copper phthalocyanine (CuPc) as the donor material. The interaction between MoO3 and CuPc is detected using UV–visible absorption and X-ray photoelectron spectroscopy. The electron transfer between MoO3 and CuPc causes the formation of an interface state at the MoO3/CuPc interface, resulting in Fermi-level pinning at the interface. Consequently, inserting a MoO3 anode buffer layer cannot improve the efficiency of the CuPc/C60 heterojunction device.
In Section 1 of Chapter 4, the effect of PSCs fabricated using various solvents is studied. The device was composed of an ITO/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) / CH3NH3PbI3 (fabricated using various solvents) / C60/bathocuproine (BCP) / Ag structure. The solvents are dimethylformamide (DMF), γ-butyrolactone (GBL), dimethyl sulfoxide (DMSO), a mixture of DMSO and DMF (DMSO:DMF; 1:1 v/v), and a mixture of DMSO and GBL (DMSO:GBL; 1:1 v/v). As a result, a power conversion efficiency (PCE) of 9.77% was obtained using the mixed solvent of DMSO:GBL because of smooth surface roughness, uniform film coverage on the substrate, and high crystallization of perovskite structure. Finally, the mixed solvent of DMSO:DMF:GBL (5:2:3 v/v/v), which combined the advantage of each solvent at an appropriate ratio, was used to fabricate the device, thereby leading to the further improvement of the PCE of PSCs to 10.84%. In Section 2 of Chapter 4, the effects of PSCs using different temperature annealing treatments and various materials as acceptors are studied. The device was composed of an ITO/PEDOT:PSS/CH3NH3PbI3 (different temperature annealing treatments) / acceptor materials/ BCP / Ag structure. The thermal annealing treatments of CH3NH3PbI3 layers were conducted from 60 °C to 120 °C. Results show that the temperature of the annealing treatment has significant influences on the PCE of the device. The acceptor materials used in the device were C60, C70, and 3,4,9,10-perylenetetracarboxylic bisbenzimidazole. This finding shows that the mechanism of PSCs is similar to the concept of OSCs, in which the donor/acceptor interface dissociates the electron–hole pair via the energy level difference to produce the photovoltaic effect. Therefore, an efficiency of 11.58% was obtained in CH3NH3PbI3 PSC.

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