高效聚合物和硫化鉛膠體量子點太陽電池及其光電性能的研究
發(fā)布時間：2018-08-22 17:11
【摘要】：從太陽光中直接獲取能量的光伏技術(shù)被認為是最有潛力解決能源危機的方法之一。盡管傳統(tǒng)無機太陽電池已經(jīng)取得了巨大的進步和發(fā)展，但原材料價格昂貴和生產(chǎn)成本較高限制了其大規(guī)模應用。近年來，以聚合物太陽電池和膠體量子點太陽電池為代表的新型太陽電池技術(shù)引起了學術(shù)界和工業(yè)界的廣泛關(guān)注。通過改變聚合物材料的分子結(jié)構(gòu)，能夠調(diào)節(jié)材料的帶隙和載流子遷移率等參數(shù)，使得聚合物太陽電池的材料選擇范圍更加廣泛。通過改變量子點的尺寸、形狀、組分和聚集形態(tài)可以對其電學和光學性質(zhì)進行調(diào)節(jié)，使得膠體量子點太陽電池能夠吸收利用太陽光譜中的可見光和紅外光。這兩種新型太陽電池技術(shù)同時都具備溶液加工、制備工藝簡單、低成本和可制備大面積柔性器件等優(yōu)點，已經(jīng)成為光電材料與器件領(lǐng)域的研究熱點。目前溶液加工的聚合物太陽電池和膠體量子點太陽電池的最高能量轉(zhuǎn)換效率分別達到了10.6%和7.4%，但距離實際應用仍然有一段距離。本博士學位論文的工作主要包括基于低溫溶液加工方式制備的高效率柔性聚合物太陽電池和PbS膠體量子點太陽電池及其光電性能研究，同時研究了溶劑處理方法對聚合物太陽電池的活性層形貌和光伏性能的影響，為采用溶液加工方式制備低成本的新型太陽電池技術(shù)提供有價值的參考。 在第一部分工作中，我們采用倒置器件結(jié)構(gòu)，獲得了能量轉(zhuǎn)換效率為8.71%的高效柔性聚合物太陽電池，器件的短路電流達到17.9mA cm-2，開路電壓達到0.74V，填充因子為65.9%。這一結(jié)果得到了國家光伏質(zhì)檢中心的獨立認證，是目前文獻公開報道的最高效率。研究發(fā)現(xiàn)，醇溶性聚合物聚[(9,9-二(3’-(N,N-二甲基胺)丙基)-2,7-芴)-alt-2,7-(9,9-二辛基芴)](PFN)可以降低聚對苯二甲酸乙二醇酯襯底氧化銦錫(PET/ITO)的表面粗糙度和功函數(shù)，使得ITO與活性層之間形成利于電子輸運的歐姆接觸，有利于載流子的收集。這種高效柔性聚合物太陽電池的穩(wěn)定性同樣優(yōu)異，器件在空氣中放置120天，能量轉(zhuǎn)換效率仍能維持初始效率的92%。在彎曲條件下測試，器件的光伏性能并沒有發(fā)生明顯的衰減。上述優(yōu)異的性能為柔性聚合物太陽的實際應用打下良好基礎(chǔ)。柔性聚合物太陽電池的理論質(zhì)量功率可達到400W Kg-1，大大高于基于單晶硅的電池模組的功率密度，，而與最好性能的薄膜電池相媲美。這一優(yōu)點使得這種電池有望在便攜電源和空間衛(wèi)星等領(lǐng)域得到應用。低溫溶液加工是這種高效聚合物太陽電池的最突出優(yōu)點，器件在制備過程中沒有采用任何的熱處理工藝，為在室溫條件下高效大面積柔性聚合物太陽電池的工業(yè)化生產(chǎn)提供了一種參考方法。 聚合物太陽電池的光伏性能與活性層的形貌密切相關(guān)。在第二部分工作中，我們采用溶劑退火的處理方法對活性層的形貌進行優(yōu)化，提高了聚合物太陽的光伏性能，并探討了其作用機理。對于基于P3HT/PCBM體系的聚合物太陽電池，結(jié)合這一優(yōu)化和使用ZnO/PFN作為陰極修飾層，器件的能量轉(zhuǎn)換效率達到了4.53%。在此基礎(chǔ)上，以溶液加工的V2O5代替蒸鍍的MoO3作為空穴抽取層材料，制備了能量轉(zhuǎn)換效率為3.66%的全溶液加工P3HT/PCBM體系聚合物太陽電池。我們同時考察了低沸點溶劑退火對基于D-A型窄帶隙聚合物電子給體材料的太陽電池的影響，我們認為低沸點溶劑退火能夠誘導活性層中給體、受體相發(fā)生相分離，從而優(yōu)化活性層形貌，增強薄膜光吸收和載流子遷移率。能量轉(zhuǎn)換效率的提高主要來源于填充因子的貢獻。這種低沸點溶劑退火方法具有一定的通用性，活性層薄膜經(jīng)低沸點溶劑處理過程之后，PDTBDTFTQ/PC71BM體系聚合物太陽電池的能量轉(zhuǎn)換效率從5.21%提高到7.25%，填充因子從49.9%提高到74.1%。SFTBT/PC71BM體系有機小分子太陽電池的能量轉(zhuǎn)換效率從1.88%提高到3.39%。PCDTBT/PC71BM體系聚合物太陽電池的能量轉(zhuǎn)換效率從5.16%提高到7.03%。研究結(jié)果表明，低沸點溶劑退火的處理時間對器件的光伏性能有重大影響，溶劑退火時間過長容易引起給/受體相分離程度過度擴大，增大了載流子復合的概率，從而降低了器件的短路電流和能量轉(zhuǎn)換效率。 在第三部分工作中，我們采用有機/無機復合配體鈍化方法，獲得了分散性良好、尺寸均勻的硫化鉛(PbS)量子點，制備了高效率的肖特基結(jié)構(gòu)PbS膠體量子點太陽電池。器件的開路電壓和能量轉(zhuǎn)換效率分別為0.54V和3.72%。論文討論了復合配體中不同烷基鏈長度的有機配體對PbS膠體量子點的尺寸、分散性、晶體結(jié)構(gòu)和吸收光譜的影響。我們研究了不同烷基鏈長度的保護溶劑對PbS膠體量子點太陽電池光伏性能的影響，烷基鏈較長的油胺制備的PbS肖特基太陽電池性能最優(yōu)，能量轉(zhuǎn)換效率達到3.52%。研究還表明，在PbS膠體量子點太陽電池中引入醇溶性聚合物材料PFN作為陰極界面修飾層，可有效降低器件的漏電流，并提高器件的填充因子和能量轉(zhuǎn)換效率。
[Abstract]:Photovoltaic technology is considered as one of the most promising solutions to the energy crisis. Although traditional inorganic solar cells have made tremendous progress and development, their large-scale applications have been limited by the high cost of raw materials and production. Point solar cells have attracted much attention in academia and industry. By changing the molecular structure of polymer materials, the band gap and carrier mobility of polymer materials can be adjusted, so that the material selection range of polymer solar cells can be wider. Composition and aggregation morphology can be used to adjust their electrical and optical properties, so that colloidal quantum dot solar cells can absorb and utilize visible and infrared light in the solar spectrum. At present, the maximum energy conversion efficiency of polymer solar cells and colloidal quantum dot solar cells processed by solution is 10.6% and 7.4% respectively, but it is still a long way from practical application. High-efficiency flexible polymer solar cells and PBS colloidal quantum dots solar cells and their photoelectric properties were studied. The effect of solvent treatment on the morphology of active layer and photovoltaic properties of polymer solar cells was also studied.
In the first part of the work, we used inverted device structure to obtain high efficiency flexible polymer solar cells with energy conversion efficiency of 8.71%. The short-circuit current of the solar cells reached 17.9 mA cm-2, the open-circuit voltage reached 0.74 V, and the filling factor was 65.9%. This result has been independently certified by the National Photovoltaic Quality Inspection Center and is now published in the literature. It was found that the surface roughness and work function of poly (9,9-bis(3'-(N,N-dimethylamine) propyl) - 2,7-fluorene) - alt-2,7-(9,9-dioctylfluorene)] (PFN) on polyethylene terephthalate (PET/ITO) substrate could be reduced by the alcohol-soluble polymer, resulting in the formation of an Ohmic junction between ITO and the active layer, which is conducive to electron transport. The high-efficiency flexible polymer solar cell also has excellent stability. The energy conversion efficiency of the device can still maintain 92% of the initial efficiency after 120 days in the air. The photovoltaic performance of the device has not been significantly attenuated under bending conditions. The theoretical mass power of flexible polymer solar cells can reach 400W Kg-1, which is much higher than the power density of single crystal silicon based solar cell modules, and is comparable to the best performance thin film solar cells. This advantage makes this kind of solar cells hopeful to be used in portable power sources and space satellites. Liquid processing is the most prominent advantage of this kind of high-efficiency polymer solar cell. No heat treatment process is used in the preparation of the device, which provides a reference method for the industrial production of high-efficiency large-area flexible polymer solar cells at room temperature.
The photovoltaic performance of polymer solar cells is closely related to the morphology of the active layer. In the second part, we optimize the morphology of the active layer by solvent annealing, improve the photovoltaic performance of polymer solar cells, and explore its mechanism. An energy conversion efficiency of 4.53% was achieved by optimizing and using ZnO/PFN as the cathode modification layer. On this basis, the polymer solar cells with energy conversion efficiency of 3.66% were prepared by using V2O5 processed in solution instead of MoO3 evaporated as the hole extraction layer. The influence of annealing agent on D-A type narrow band gap polymer electron donor solar cells is discussed. We believe that low boiling point solvent annealing can induce donor and acceptor phase separation in the active layer, thus optimizing the morphology of the active layer, enhancing the optical absorption and carrier mobility of the films. The energy conversion efficiency of PDTBDTFTQ/PC71BM polymer solar cells increased from 5.21% to 7.25%, and the filling factor increased from 49.9% to 74.1%. The energy conversion of SFTBT/PC71BM organic small molecule solar cells was also improved. The energy conversion efficiency of PCDTBT/PC71BM polymer solar cells increased from 5.16% to 7.03%. The results show that the treatment time of low boiling point solvent annealing has a significant effect on the photovoltaic performance of the devices. The long annealing time of the solvents tends to cause excessive separation of donor/acceptor phase and increase the load. The probability of current recombination reduces the short circuit current and energy conversion efficiency of the device.
In the third part of the work, we used the organic/inorganic complex ligand passivation method to obtain well-dispersed lead sulfide (PbS) quantum dots with uniform size. High-efficiency Schottky structure PbS colloidal quantum dot solar cells were prepared. The open-circuit voltage and energy conversion efficiency of the devices were 0.54V and 3.72% respectively. The effects of organic ligands with different alkyl chain lengths on the size, dispersion, crystal structure and absorption spectra of PbS colloidal quantum dots were investigated. The effects of protective solvents with different alkyl chain lengths on the photovoltaic performance of PbS colloidal quantum dots solar cells were investigated. The conversion efficiency is 3.52%. The study also shows that the introduction of alcohol-soluble polymer PFN as cathode interface modification layer in PbS colloidal quantum dot solar cells can effectively reduce the leakage current of the device, and improve the filling factor and energy conversion efficiency.
【學位授予單位】：華南理工大學
【學位級別】：博士
【學位授予年份】：2014
【分類號】：TM914.4
本文編號：2197774
[Abstract]:Photovoltaic technology is considered as one of the most promising solutions to the energy crisis. Although traditional inorganic solar cells have made tremendous progress and development, their large-scale applications have been limited by the high cost of raw materials and production. Point solar cells have attracted much attention in academia and industry. By changing the molecular structure of polymer materials, the band gap and carrier mobility of polymer materials can be adjusted, so that the material selection range of polymer solar cells can be wider. Composition and aggregation morphology can be used to adjust their electrical and optical properties, so that colloidal quantum dot solar cells can absorb and utilize visible and infrared light in the solar spectrum. At present, the maximum energy conversion efficiency of polymer solar cells and colloidal quantum dot solar cells processed by solution is 10.6% and 7.4% respectively, but it is still a long way from practical application. High-efficiency flexible polymer solar cells and PBS colloidal quantum dots solar cells and their photoelectric properties were studied. The effect of solvent treatment on the morphology of active layer and photovoltaic properties of polymer solar cells was also studied.
In the first part of the work, we used inverted device structure to obtain high efficiency flexible polymer solar cells with energy conversion efficiency of 8.71%. The short-circuit current of the solar cells reached 17.9 mA cm-2, the open-circuit voltage reached 0.74 V, and the filling factor was 65.9%. This result has been independently certified by the National Photovoltaic Quality Inspection Center and is now published in the literature. It was found that the surface roughness and work function of poly (9,9-bis(3'-(N,N-dimethylamine) propyl) - 2,7-fluorene) - alt-2,7-(9,9-dioctylfluorene)] (PFN) on polyethylene terephthalate (PET/ITO) substrate could be reduced by the alcohol-soluble polymer, resulting in the formation of an Ohmic junction between ITO and the active layer, which is conducive to electron transport. The high-efficiency flexible polymer solar cell also has excellent stability. The energy conversion efficiency of the device can still maintain 92% of the initial efficiency after 120 days in the air. The photovoltaic performance of the device has not been significantly attenuated under bending conditions. The theoretical mass power of flexible polymer solar cells can reach 400W Kg-1, which is much higher than the power density of single crystal silicon based solar cell modules, and is comparable to the best performance thin film solar cells. This advantage makes this kind of solar cells hopeful to be used in portable power sources and space satellites. Liquid processing is the most prominent advantage of this kind of high-efficiency polymer solar cell. No heat treatment process is used in the preparation of the device, which provides a reference method for the industrial production of high-efficiency large-area flexible polymer solar cells at room temperature.
The photovoltaic performance of polymer solar cells is closely related to the morphology of the active layer. In the second part, we optimize the morphology of the active layer by solvent annealing, improve the photovoltaic performance of polymer solar cells, and explore its mechanism. An energy conversion efficiency of 4.53% was achieved by optimizing and using ZnO/PFN as the cathode modification layer. On this basis, the polymer solar cells with energy conversion efficiency of 3.66% were prepared by using V2O5 processed in solution instead of MoO3 evaporated as the hole extraction layer. The influence of annealing agent on D-A type narrow band gap polymer electron donor solar cells is discussed. We believe that low boiling point solvent annealing can induce donor and acceptor phase separation in the active layer, thus optimizing the morphology of the active layer, enhancing the optical absorption and carrier mobility of the films. The energy conversion efficiency of PDTBDTFTQ/PC71BM polymer solar cells increased from 5.21% to 7.25%, and the filling factor increased from 49.9% to 74.1%. The energy conversion of SFTBT/PC71BM organic small molecule solar cells was also improved. The energy conversion efficiency of PCDTBT/PC71BM polymer solar cells increased from 5.16% to 7.03%. The results show that the treatment time of low boiling point solvent annealing has a significant effect on the photovoltaic performance of the devices. The long annealing time of the solvents tends to cause excessive separation of donor/acceptor phase and increase the load. The probability of current recombination reduces the short circuit current and energy conversion efficiency of the device.
In the third part of the work, we used the organic/inorganic complex ligand passivation method to obtain well-dispersed lead sulfide (PbS) quantum dots with uniform size. High-efficiency Schottky structure PbS colloidal quantum dot solar cells were prepared. The open-circuit voltage and energy conversion efficiency of the devices were 0.54V and 3.72% respectively. The effects of organic ligands with different alkyl chain lengths on the size, dispersion, crystal structure and absorption spectra of PbS colloidal quantum dots were investigated. The effects of protective solvents with different alkyl chain lengths on the photovoltaic performance of PbS colloidal quantum dots solar cells were investigated. The conversion efficiency is 3.52%. The study also shows that the introduction of alcohol-soluble polymer PFN as cathode interface modification layer in PbS colloidal quantum dot solar cells can effectively reduce the leakage current of the device, and improve the filling factor and energy conversion efficiency.
【學位授予單位】：華南理工大學
【學位級別】：博士
【學位授予年份】：2014
【分類號】：TM914.4
【參考文獻】
相關(guān)博士學位論文 前3條
1 楊庭斌;新型結(jié)構(gòu)聚合物太陽電池與光探測器的制備及其性能研究[D];華南理工大學;2012年
2 何志才;基于電極界面層調(diào)控實現(xiàn)電池高效聚合物太陽池的研究[D];華南理工大學;2013年
3 汪青;界面修飾聚合物電致發(fā)光器件及其物理機制研究[D];華南理工大學;2013年
本文編號：2197774
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