银铜双原子金属辅助化学腐蚀法制备多晶黑硅太阳电池

发布时间：2018-11-16 08:40

【摘要】：当今光伏市场,晶硅电池占据了90%以上的市场份额,而多晶硅太阳电池由于成本较低,切片方式简单成为了科研工作者以及光伏企业的研究热点。但是由于多晶硅片表面较高的反射率造成了大量入射光的损失,即使经酸制绒处理后的表面反射率也有24%左右,使得多晶硅太阳电池的效率始终无法得到有效的提升,难以满足人们的要求。黑硅材料是一种从紫外至近红外波段均有较低反射率的材料,在太阳电池领域有着非常好的应用前景,但现阶段对黑硅材料的研究大部分处于实验室阶段,如何将其有效地应用到多晶硅太阳电池的制备过程中是本文的主要研究内容。本文首先采用AgNO3/Cu(NO3)2/HF/H2O2双原子体系辅助化学腐蚀法在常温下制备出具有优异陷光性能的多晶黑硅结构,通过添加微量的Ag催化Cu腐蚀能够在常温下进行,相对于制备黑硅的其他方法,该方法成本低且更具有工业生产的可行性。研究了不同腐蚀参数对所制备黑硅材料的形貌及反射率的影响,并探究了Ag/Cu双原子协同催化腐蚀的机理。研究结果表明,腐蚀液中的HF、H2O2浓度,Ag/Cu元素摩尔浓度比以及腐蚀时间对所制备的黑硅材料的结构形貌以及反射率有着非常重要的影响,最终在HF浓度为1.8M,H2O2浓度为0.4M,Ag:Cu元素摩尔比为1:5,腐蚀时间为180s时制备出了具有最佳陷光性能的制备态黑硅样品,400-900nm波长范围内的平均反射率为4.74%。但是一味地追求低反射率却不能得到高效率的太阳电池,原因在于制备态黑硅材料表面较多的缺陷态会严重影响扩散形成的p-n结质量以及钝化性能。因此,本文创新性地添加一道纳米重构(Nano-structure rebuilding,NSR)工艺对制备态的黑硅纳米结构进行扩孔处理,可控制备出规则的倒金字塔陷光结构,并采用原子层沉积(Atomic layer deposition,ALD)技术在制备的硅片表面生长一层Al2O3钝化层。研究了不同NSR刻蚀参数对所制备的倒金子塔黑硅样品的结构形貌,反射率以及少子寿命的影响,并探究了倒金字塔结构的形成机理。通过实验研究发现倒金字塔黑硅样品的尺寸大小、表面反射率以及少子寿命随NSR刻蚀的时间及温度的升高而增大,硅片表面的结构呈现方孔状结构向倒金字塔结构转变的趋势。通过改变NSR刻蚀时间及温度,我们制备出了边长尺寸在100nm至900nm的倒金字塔结构;发现制备态黑硅纳米结构的深度会显著影响经NSR刻蚀后形成倒金字塔结构的最终尺寸大小。通过优化参数并结合反射率及钝化性能,600nm尺寸的倒金字塔黑硅样品表现最佳,钝化后400-900nm波长范围内平均反射率为8.87%,少子寿命为37.82μs。将上述制备的不同尺寸的倒金字塔结构样品以及制备态黑硅样品进行多晶太阳电池的制备,发现600nm尺寸大小的倒金字塔样品表现出十分优异的电池性能,其短路电流Isc,开路电压Voc以及填充因子FF分别为8.962A,631mV以及79.95%,最终制备的太阳电池平均效率为18.58%,高出产线普通酸制绒电池0.58%;同时研究了Ag/Cu双原子MACE法与NSR技术对金刚线切割多晶硅片的制绒效果,研究发现经Ag/Cu双原子MACE法与NSR刻蚀后,金刚线切割多晶硅片表面切割痕几乎消失不见,同样采用倒金字塔尺寸为600nm的金刚线切割硅片样品制备出了性能最佳的太阳电池,其开路电压Voc为632mV,短路电流Isc为8.980A,填充因子FF为80.18%,平均效率为18.71%,高于同结构的砂浆切割电池,本文所开发的工艺路线为实现高效金刚线切割多晶太阳电池的产业化生产提供了有效的技术思路。
[Abstract]:In the current photovoltaic market, the crystalline silicon battery occupies more than 90% of the market share, and the polycrystalline silicon solar cell has the advantages of low cost and simple slicing mode, and has become the research hotspot of the scientific research worker and the photovoltaic enterprise. but due to the high reflectivity of the surface of the polysilicon sheet, the loss of a large amount of incident light is caused, and the surface reflectance after the acid-based pile treatment is about 24%, so that the efficiency of the polycrystalline silicon solar cell can not be effectively improved, and the requirement of people is difficult to meet. The black silicon material is a material with lower reflectivity from the ultraviolet to the near infrared band, has a very good application prospect in the field of solar cells, How to apply it to the preparation of the polycrystalline silicon solar cell is the main research content in this paper. In this paper, an AgNO3/ Cu (NO3) 2/ HF/ H2O2 double-atomic system-assisted chemical corrosion method is used to prepare a polycrystalline black silicon structure with excellent light-trapping performance at normal temperature, and the addition of trace Ag-catalyzed Cu corrosion can be carried out at normal temperature, and relative to other methods for preparing black silicon, The method is low in cost and has the feasibility of industrial production. The effect of different corrosion parameters on the morphology and reflectivity of the prepared black silicon material was studied, and the mechanism of the co-catalytic corrosion of Ag/ Cu was investigated. The results show that the concentration of HF, H _ 2O _ 2, the molar concentration of Ag/ Cu, and the corrosion time of the corrosive liquid have a very important influence on the structure and the reflectivity of the prepared black silicon material. The prepared black-silicon sample with optimal light-trapping performance was prepared at the time of the etching time of 180s, and the average reflectance in the range of 400-900nm was 4.74%. but the high efficiency solar cell can not be obtained by blindly pursuing low reflectivity, and the reason is that the defect state of the surface of the prepared black silicon material can seriously affect the p-n junction quality and the passivation performance formed by diffusion. Therefore, a nano-structure reconstruction (NSR) process is added to the preparation state of the black silicon nano-structure to be reamed, the light structure of the inverted pyramid of the prepared rule can be controlled, and the atomic layer deposition is adopted. an al2o3 passivation layer is grown on the surface of the prepared silicon wafer by an ald) technique. The effect of different NSR etching parameters on the structure, reflectivity and sub-life of the black silicon sample of the inverted-gold column prepared is studied, and the formation mechanism of the inverted pyramid structure is also explored. The results show that the size, surface reflectivity and less sub-life of the inverted pyramid black silicon sample increase with the time and temperature of the NSR etching, and the structure of the surface of the silicon chip presents the tendency of the square-hole structure to transition to the inverted pyramid structure. By changing the NSR etching time and temperature, we prepared an inverted pyramid structure with a side length of 100nm to 900nm, and found that the depth of the prepared black silicon nano-structure can significantly affect the final size of the inverted pyramid structure after the NSR etching. by optimizing the parameters and combining the reflectivity and the passivation performance, the inverted pyramid black silicon sample of 600nm size shows the best performance, the average reflectivity in the 400-900nm wavelength range after the passivation is 8.87%, the method for preparing the inverted pyramid structure with the size of 600nm shows that the inverted pyramid sample with the size of 600nm exhibits excellent battery performance and short circuit current isc, The open-circuit voltage Voc and the filling factor FF were 80.962A, 631mV and 79.95%, respectively. The average efficiency of the final solar cell was 18. 58%, and the high yield line was 0.58%. The effect of the Ag/ Cu double-atom MACE method and the NSR technique on the texturing of the diamond wire was also studied. In the study, after the Ag/ Cu double-atom MACE method and the NSR etching, the surface cut mark of the diamond wire-cut polycrystalline silicon wafer is almost disappeared, and the solar cell with the best performance is prepared by the diamond wire-cut silicon wafer sample with the inverted pyramid size of 600nm, the open-circuit voltage Voc of which is 632mV, The short-circuit current Isc is 8.980A, the filling factor FF is 80. 18%, the average efficiency is 18.71%, and the mortar cutting battery with the same structure is higher than that of the same structure.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM914.4

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