【作者】 杨靖霞；

【导师】 靳正国；

【作者基本信息】 天津大学 ， 材料学， 2010， 博士

【摘要】 以TiO₂为光阳极,CuInSe₂为无机敏化层的NPC太阳能电池造价低、易制造、大气稳定。本文采用连续离子层吸附反应（SILAR）法和电沉积法研究了CuInSe₂薄膜制备,同时采用溶胶-凝胶法研究了TiO₂薄膜制备,最后在TiO₂基底上采用电沉积法制备CuInSe₂薄膜,研究了CuInSe₂敏化TiO₂异质结构的特性。利用SILAR法制备CuInSe₂薄膜时,首次采用三乙醇胺络合Cu²⁺离子和柠檬酸钠络合In³⁺离子的双络合法制备了混合阳离子前驱体溶液,调整阳离子前躯体溶液pH值至8。结果表明,该混合阳离子溶液制备的薄膜容易实现Cu、In、Se三种元素的均匀分布。前躯体溶液水浴温度的提高可以显著加快薄膜的生长速度。当溶液中Cu/In比为1.5时,CuInSe₂薄膜中的元素比在400℃下热处理30min后比较接近1:1:2的化学计量。适当提高热处理温度和延长热处理时间均有利于改善CuInSe₂薄膜的晶化。利用电沉积法制备CuInSe₂时,采用柠檬酸钠络合Cu、In、Se元素,将溶液pH值调制6⁷之后,Se成为最难沉积的元素,由于三种元素沉积电位相差大,首次提出了采用双阶跃恒电位（DPSED）法沉积CuInSe₂薄膜,双电位参数分别为V1=-800mV,V2=-1400mV。阶跃时间的变化对沉积薄膜的组分和形貌有一定影响,阶跃时间t1=30s,t2=60s最合适。当电解液CuCl₂/InCl₃/SeO₂摩尔比为2/0.4/4⁵时,DPSED法制备的薄膜接近1:1:2的化学计量,所制备的薄膜的禁带宽度为1.05eV。溶胶-凝胶法制备介孔TiO₂时,采用钛酸异丙脂（Ti（OⁱPr）₄）为钛源,乙醛肟（CH₃CH=NOH）为络合剂,分别利用表面活性剂F127和Brij56作为成孔剂,350⁴00℃下热分解。研究表明,采用CH₃CH=NOH络合修饰的Ti（OⁱPr）₄制备的TiO₂在较高焙烧温度时,仍然可以得到具有高比表面积,小的粒径和窄的孔径分布的TiO₂材料。在350℃下煅烧之后利用F127作为成孔剂的样品的最高比表面积可达219m²/g,利用Brij56作为成孔剂的样品的最高比表面积可达283m²/g。以TiO₂为基底制备CuInSe₂时其沉积电位要比在ITO玻璃上沉积时负移近200mV,阶跃参数为V1=-1000mV, t1=30s, V2=-1600mV, t2=60s时制备CuInSe₂薄膜最接近Cu: In: Se=1:1:2的化学计量,循环6次后所制备的CuInSe₂薄膜的厚度约为300nm。ITO/TiO₂/CuInSe₂/电解液/Pt电池的最大开路电压出现在贫Cu富Se的样品,为446 mV,最大短路电流为0.0054 mA/cm²。更多还原

【Abstract】 The NPC solar cell is a very promising kind of solar cells as it is cheap, easy to manufacture and high air stability. Here TiO₂ was used as photo-anode, and CuInSe₂ as inorganic sensitizer. CuInSe₂ films were prepared both by successive ionic layers adsorption and reaction （SILAR） method and electrodeposition method on glass substrate, and TiO₂ films were prepared by Sol-Gel method. Subsequently, the CuInSe₂ films were electrodeposited on TiO₂ films to form TiO₂/CuInSe₂ heterogeneous structure.In the CuInSe₂ preparation by SILAR method, triethanolamine and sodium citrate were used to complex Cu²⁺ and In³⁺, respectively, to form the Cu and In mixed cationic precursor solutions. The results indicitated that the Cu and In mixed cationic precursor solutions resulted in more uniform distribution for Cu, In and Se elements than the separated cationic precursors. The temperature elevation of precursor solutions could accelerate the growth of CuInSe₂ films. Chalcopyrite CuInSe₂ thin film with near stoichiometry was obtained from Cu/In mol ratio =1.5 in mixed cationic precursor solution after annealed at 400℃for 30min. The suitable rise of annealing temperature and time is beneficial for improvement of CuInSe₂ crystallization.In the process of CuInSe₂ electrodeposition, sodium citrate were used to complex Cu, In and Se elements in order to tune the pH value to 6⁷. In this mild solution conditions, the deposition potentials for Cu, In, and Se elements had a big difference with each other, and Se element required the most negative potential to be deposited. Thus, one step electrodepostion with an alternating double-potentiostatic （DPSED） program was used to prepare CuInSe₂ thin films in the nearly neutral aqueous electrolytes, and the double potential parameters were V1=-800mV and V2=-1400mV. The step time had influences on the morphology and components of CuInSe₂ films, and the appropriate time were t1=30s and t2=60s. When the Cu/In/Se mol ratio was 2/0.4/4⁵ in the electrolytes, the deposited CuInSe₂ films were near to Cu: In: Se = 1:1:2 stoichiometry, and the band gap is 1.05eV.In TiO₂ Sol-Gel preparation, acetaldoxime （CH₃CH=NOH） was used as a new ligand, and F127 and Brij56 were used as pore-forming agent. The organic parts were decomposed at 350⁴00℃. The results showed that the TiO₂ prepared by CH₃CH=NOH-modified Ti（OiPr）4 could preserve high BET surface, small particle size and narrow pore distribution even at higher calcinating temperature. The highest BET surface is 219m²/g for TiO₂ sample with F127 and 283m²/g for sample with Brij56, respectively, after calcinated at 350℃.For the CuInSe₂ electrodeposition on TiO₂ substrate, the deposition potentials had nearly 200mV negative shift compared with the deposition potentials on ITO substrate. Thus the best deposition parameters were changed to V1=-1000mV, t1=30s, V2=-1600mV, t2=60s, under which the prepared CuInSe₂ films were near 1:1:2 stoichiometry. After 6 cycles, the thickness of prepared CuInSe₂ films was about 300nm. The heterogeneous solar cell was designed as ITO/TiO₂/CuInSe₂/electrolyte/Pt structure. The biggest open-circuit voltage was 446mV, and the biggest short-circuit current was 0.0054 mA/cm².更多还原