金刚线切多晶黑硅的制备及性能研究

发布时间：2018-08-17 12:46

【摘要】：晶硅电池在全球光伏市场始终占据着80%以上的份额,其中多晶硅电池连续多年成为晶硅产品的主流。近几年发展起来的金刚线硅片切割技术具有环境友好、损耗少、切片效率高等诸多优点,可使硅片单片成本降低0.4-0.6元,是公认的先进切片技术,已在单晶硅片的切割上实现了全面推广。但是该技术在多晶方面的推广遇到了很大的障碍,这是由于金刚切割片表面存在着一层非晶硅,影响了传统多晶硅HF/HNO3制绒体系的有效性。由此,亟需一种新的制绒方法来解决金刚线切多晶硅的制绒难题。在目前的解决方案中,金属催化化学刻蚀(MCCE)黑硅制备工艺由于其衬底选择性低、价格低廉、与现有产线兼容等优点,而成为业界研究的焦点。本文系统研究了多晶硅金刚片的金属银催化化学刻蚀机理、工艺技术以及不同绒面结构的光学性能。首先,研究了在HF/AgNO3/H2O2体系中,MCCE制备黑硅的机理:金属银纳米颗粒的电化学沉积以及在银纳米颗粒催化下硅原子被双氧水氧化并被氢氟酸溶解的过程。随后,研究了各成分配比对黑硅结构及其光学性能的影响,并通过配比优化得到了一种用于做电池的黑硅结构。由于未经后处理的黑硅结构表面粗糙,导致复合较大,严重影响电池的性能,需要对黑硅结构进行优化。因此,接下来研究了黑硅结构的优化工艺。采用KOH/IPA的混合溶液对黑硅结构进行优化,得到纳米倒金字塔、纳米金字塔、纳米方孔、纳米圆坑等一系列结构,且其表面光滑、开口大,反射率低于15%。采用预处理的156.75*156.75mm2金刚线切P型多晶硅片经金属银催化刻蚀方法制得黑硅结构并优化后,结合产线工艺完成金刚线切黑硅电池的制备。制备得到的黑硅电池较砂浆切常规电池短路电流ISC提升114.9mA,开路电压VOC并未降低,填充因子FF提升0.74%,最终使得转换效率提升0.32%。金刚线切黑硅电池优异的性能证明了MCCE制备黑硅的工艺在解决金刚线切多晶硅制绒难题以及提升电池性能方面具有巨大的优势,同时,由于此套工艺简单,与产线工艺完美兼容,非常适合商业化生产。
[Abstract]:Crystal silicon cells have always occupied more than 80% of the global photovoltaic market, among which polysilicon cells have been the mainstream of crystal silicon products for many years. The wafer cutting technology developed in recent years has many advantages, such as friendly environment, low loss, high chip efficiency and so on. It can reduce the cost of monolithic silicon wafer by 0.4-0.6 yuan, which is recognized as an advanced slicing technology. It has been widely used in the cutting of single crystal silicon wafer. However, the popularization of this technology in polycrystal has encountered great obstacles, which is due to the existence of a layer of amorphous silicon on the surface of the diamond chip, which affects the effectiveness of the traditional polysilicon HF/HNO3 velvet system. Therefore, a new method is urgently needed to solve the problem of making polysilicon. In the current solution, metal-catalyzed chemical etching of (MCCE) black silicon has become the focus of research due to its low substrate selectivity, low price and compatibility with existing production lines. In this paper, the mechanism of silver catalyzed chemical etching of polysilicon wafers, the process technology and the optical properties of different suede structures have been systematically studied. Firstly, the mechanism of preparing black silicon in HF/AgNO3/H2O2 system was studied: electrochemical deposition of silver nanoparticles and oxidation of silicon atoms by hydrogen peroxide and dissolution by hydrofluoric acid under the catalysis of silver nanoparticles. Then, the influence of the composition ratio on the black silicon structure and its optical properties was studied, and a kind of black silicon structure was obtained by optimizing the ratio. Due to the rough surface of the black silicon structure without post-treatment, it is necessary to optimize the black silicon structure because of the large composition, which seriously affects the performance of the battery. Therefore, the optimization process of black silicon structure is studied. The structure of black silicon was optimized by using the mixed solution of KOH/IPA. A series of structures, such as nanometer inverted pyramid, nanometer square hole and nanometer round pit, were obtained. The surface of the structure was smooth, the opening was large, and the reflectivity was lower than 15%. The black silicon structure was prepared by the metal silver catalytic etching method with the pretreated 156.75*156.75mm2 linear cut P polysilicon wafer, and the fabrication of the silicon battery was completed by the combination of the production line process and the metal silver catalytic etching method. The prepared black silicon battery has a short circuit current of 114.9 Ma, an open circuit voltage of 114.9 Ma, a filling factor FF of 0.74 and a 0.32% increase of conversion efficiency. The excellent performance of diamond wire cut black silicon battery proves that the process of preparing black silicon by MCCE has great advantages in solving the problem of making velvet and improving the performance of the battery. At the same time, because of the simplicity of this process, Perfect compatibility with production line process, very suitable for commercial production.
【学位授予单位】：中国科学院大学(中国科学院物理研究所)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN304.12;TM914.4

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