不同形貌的金字塔结构对硅片表面钝化和异质结太阳电池的影响

Influence of Different Pyramidal Structural Morphologies of Crystalline Silicon Wafers for Surface Passivation and Heterojunction Solar Cells

在晶体硅表面沉积本征非晶硅层的异质结(SHJ)太阳电池以其高效率、高稳定性、低成本和低温制备等诸多优势被人们广泛关注.在晶体硅衬底表面制绒,是提高太阳电池效率的有效途径之一.本文采用四甲基氢氧化铵(TMAH)在硅片表面制备了不同形貌的金字塔结构的硅异质结电池衬底,并应用到电池中.通过研究不同金字塔的形貌,光学特性以及电学特性,找出提高硅片钝化效果,改善异质结电池的性能的优化的金字塔结构.结果表明:2%(w)TMAH,10%(w)异丙醇(IPA)可以在硅片表面制得标准四面体金字塔结构.和其它两种金字塔结构相比较,标准四面体金字塔结构绒面衬底反射率最低,可以提高太阳电池的短路电流密度(Jsc).同时,这种结构金字塔形貌可以提高钝化效果,改善电池各项性能参数.

Silicon heterojunction （SHJ） solar cells consisting of a hydrogenated amorphous silicon （a-Si：H） film deposited on a crystalline silicon wafer have attracted considerable attention from the photovoltaic industry, because of their high efficiencies, high stabilities, low cost, and low-temperature fabrication. Texturing of silicon surfaces is an effective method for improving the efficiency of silicon solar cells. In this work, textured silicon substrates consisting of three different pyramidal structures were obtained using tetramethylammonium hydroxide （TMAH） solution, and used to fabricate SHJ solar cells. We investigated the influence of different pyramidal structural morphologies on the optical properties and electronic performances, to identify the optimum structure for SHJ solar cells. We obtained a standard silicon substrate with four-sided pyramidal structures using 2% （w） TMAH and 10% （w） isopropyl alcohol （IPA）. In comparison with other pyramidal structures, the standard four-sided pyramidal-structured silicon substrate had the lowest reflectance, leading to an increased short-circuit current density （Jsc）, and its morphology is suitable for surface passivation and SHJ solar cells.