太阳能电池用玻璃粉化学镀银的研究及应用

发布时间：2018-03-19 01:35

本文选题：太阳能电池　切入点：正面银浆　出处：《中南大学》2014年硕士论文　论文类型：学位论文

【摘要】：：太阳能电池正面银浆主要由导电相银粉、无极粘接相玻璃粉、有机载体以及添加剂组成,在提高太阳能电池光电转换效率方面起到关键作用。目前太阳能电池正面银浆的主要技术以及生产销售都掌握在外国公司,国内研究起步较晚。纳米银粉颗粒度小、熔点低,在电极浆料中引入有利于形成高质量的欧姆接触。本课题采用一种新型的无锡无钯活化工艺,成功地在玻璃粉表面包覆上了一层分布均匀、致密的纳米银颗粒。本文研究了不同化学镀银法制备的银包玻璃粉的优缺点,优化了银包玻璃粉的制备工艺,并用实验所制备得到的银包玻璃粉制备了正面银浆及正面电极。借助环境扫描电子显微镜(ESEM, Quanta-200)、X射线衍射仪(XRD,D/Max2500)和原子吸收分光光度计(HG-9602)对所制备得到的银包玻璃粉的形貌和成分,纳米银颗粒的粒径、含量,烧结后电极的形貌进行了检测和分析；采用太阳能电池测试系统和四探针测试仪测定了太阳能电池的光电性能。主要研究结果如下： 1、利用乙二醇作还原剂直接使Ag+还原成Ag0而沉积在玻璃粉上,从而实现了对浆料用玻璃粉的活化,将活化后的玻璃粉分别直接加入到两种镀银液中,成功实现了对玻璃粉的镀银。研究了镀液组分及工艺条件对镀液稳定性的影响：随着氨水用量的增加,银离子的络合程度增强,镀液稳定性增强,同时镀液的pH值也升高,使镀液稳定性减弱,当氨水用量为100ml·L-1时,镀液的稳定性最好；随着温度的升高,镀液自分解能力增强；超声波对镀银液产生搅拌和高能量输入,使镀液反应加快,同时也有利于粉体的分散；pH值增大,将提高甲醛的还原能力,导致镀液容易自分解。 2、探讨了传统化学镀银法(金属离子敏化活化法)制备银包玻璃粉的可行性,结果表明此法存在以下缺点：(1)镀银前需粗化处理,否则容易导致包覆不均匀,生成较多的游离银单质。然而粗化会造成一定程度的选择性腐蚀,改变基体成分；(2)敏化时要使用大量的盐酸及氯化钠,由于敏化活化层为胶状物质,容易吸附杂质,因此难将预处理后残留的氯离子洗干净。笔者通过实验发现用去离子水洗涤20次后的玻璃粉中仍残留大量氯离子,而残留的氯离子对太阳能电池的光电转换效率影响很大。洗涤次数过多又会造成亚锡离子的氧化,影响后续镀银效果；(3)活化时若使用贵金属钯,成本较高。(4)实验中用到的锡离子会对人体产生一定程度的损害。 3、研究了活化温度、pH值以及装载量等对银包玻璃粉表面形貌的影响：活化温度对纳米银颗粒的密度和分布有很大的影响,当活化温度为5℃时,玻璃粉上纳米银很少,只有断面包覆的较为完整；当活化温度为15℃时,玻璃粉光滑面上包覆的银颗粒的密度明显增加；当活化温度为25℃时,玻璃粉表面的银单质包覆均匀,较为完整,密度最大。pH值对纳米银颗粒的粒径有很大的影响,随着pH值的升高,银单质的粒径随之变大,当pH值分别为11.8、12.6和13.4,装载量为30g·L-,活化温度为25℃时,由谢乐公式计算出晶粒粒径分别约为15nm、40nm、100nm。此外,反应时间、反应物浓度、装载量、添加方式、添加剂和有无超声也会影响到银包玻璃粉的形貌和银的析出量。 4、将没有进行任何处理的玻璃粉和银包玻璃粉制备成浆料和电极进行对比,发现银包玻璃粉对太阳能电池正面电极孔洞率的减小以及光电性能的提高起到较大的作用。相对于镀银之前,太阳能电池的光电转换效率提高了0.1%。另外,银包玻璃粉的形貌对导电厚膜的形貌电学性能以及太阳能电池的性能有显著影响。当玻璃粉表面的银的比重较高,颗粒为类球状,分布均匀,面密度较大时,导电厚膜的方阻较小,同时太阳能电池的光电转换效率较高。
[Abstract]:Solar battery positive silver paste is mainly composed of conductive silver powder, glass powder non-polar bonding phase, organic carrier and additive, play a key role in improving the conversion efficiency of solar battery. The main technologies of solar battery positive silver paste and production and sales are in the hands of foreign companies, domestic research started later. The nano silver particles small, low melting point, in the electrode paste is beneficial for forming an ohmic contact of high quality. This paper uses a new Wuxi palladium free activation process successfully in glass powder coated with a layer of uniform distribution of nano silver particles and compact.
This paper studies the advantages and disadvantages of different chemical silver plating preparation of silver coated glass powder, optimization of preparation process of silver coated glass powder, and the powder was prepared for silver coated glass positive silver paste and positive electrode was prepared. By using environmental scanning electron microscopy (ESEM, Quanta-200), X ray diffractometer (XRD D/Max2500), and atomic absorption spectrophotometer (HG-9602) morphology and composition of silver coated glass powder on the prepared nano silver particles, particle size, content, sintering, detection and analysis of electrode morphology; photovoltaic performance determination of the test system and four probe tester using solar energy the battery. The main results are as follows:
1, using ethylene glycol as the reducing agent to direct reduction of Ag+ to Ag0 and deposited on the glass powder, so as to achieve slurry by activated glass powder, the activated glass powder were added directly to the two kinds of silver plating solution, successfully realized the glass powder with silver. The bath components and influence of process conditions on the stability of plating solution with the increase of the dosage of ammonia, silver ion complexation enhancement, bath stability enhancement, while the pH value of the plating bath is increased, the stability of the bath was reduced, when the amount of ammonia is 100ml / L-1, the stability of the bath is best; with the increase of temperature, plating since the liquid decomposition ability enhancement; ultrasonic stirring and high energy input of silver plating solution, plating solution to accelerate the reaction, but also conducive to the spread of powder; the pH value increases, will improve the reducing ability of formaldehyde, lead plating solution easily from decomposition.
2, discusses the traditional method of electroless silver plating (metal ion sensitization and activation method) feasibility of preparing silver coated glass powder. The results show that this method has the following disadvantages: (1) silver before the roughening treatment, otherwise easily lead to uneven coating, generate more free silver. However, coarsening will cause a certain degree of selective corrosion and the change of matrix composition; (2) sensitized to use large amounts of hydrochloric acid and sodium chloride, due to sensitization and activation layer of gelatinous material, easy to adsorb impurities, so it is difficult for the chloride pretreatment residue after washed by experiment. The author found that a large number of residual chlorine ion with deionized water after washing 20 times the glass powder is still, while the photoelectric conversion efficiency of solar cells on the residual chlorine ion influence. The oxidation times of washing too much will cause the stannous ion, subsequent silver plating effect; (3) activation when using noble metal palladium, high cost. (4) the tin ions used in the experiment will cause a certain degree of damage to the human body.
3, the effects of activation temperature, pH value and impact load of silver coated glass powder surface activation temperature on the density and distribution of silver nanoparticles have great influence, when the activation temperature is 5 degrees centigrade, nano silver seldom glass powder, only the complete coating section; when the activation temperature is 15 C, the silver particles of glass powder coated on the smooth surface of the density was significantly increased; when the activation temperature is 25 degrees centigrade, glass powder on the surface of silver coated evenly, more complete, the maximum density of.PH value on the nano silver particle size has a great impact, with the increase of pH value, the particle size of Ag becomes large. When the pH value was 11.8,12.6 and 13.4 respectively, loading capacity of 30g - L-, activation temperature is 25 degrees centigrade by Scherrer formula to calculate the grain size were about 15nm, 40nm, 100nm. in addition, reaction time, reactant concentration, loading, add, and additive No ultrasound can also affect the morphology and precipitation of silver silver coated glass powder.
4, there will be no any treatment of glass powder and silver coated glass powder preparation into slurry and electrode were compared, found that the decrease of the front electrode silver coated glass powder on the rate of holes in solar cells and improve the photoelectric properties play a important role. Compared with the silver before the photoelectric conversion efficiency of solar cell is increased by 0.1%. in addition, there are significantly affects the performance of silver coated glass powder morphology of conductive thick film electrical properties and morphology of solar cells. When a higher proportion of glass powder on the surface of silver particles, spherical shape, uniform distribution, surface density, small resistance of conductive thick film, and high photoelectric conversion efficiency of solar cells.

【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB306;TM914.4

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