异质结太阳电池硅衬底绒面陷光结构的优化

Optimization of Light Trapping Structure on Textured Silicon Substrate for Heterojunction Solar Cells

硅异质结(SHJ)太阳电池作为备受关注的新型高效太阳电池,是在单晶硅表面沉积非晶硅薄膜制备而成的。将绒面结构的单晶硅衬底应用于异质结太阳电池,可以减少光的反射,增强光吸收的效率,从而提高太阳电池短路电流密度。利用湿法化学腐蚀对单晶硅衬底表面进行制绒,通过优化影响绒面形貌的几个关键参数,包括异丙醇浓度、时间、衬底类型和硅酸钠的含量,最终通过在n型单晶硅衬底上制绒,使波长为1011 nm处最低反射率从制绒前的34.7%降低到了9.14%,将制绒衬底应用到异质结太阳电池上,短路电流由32.06 m A/cm-2提升到36.16 m A/cm-2,有效地改善了SHJ太阳电池的性能。

Silicon heterojunction （SHJ） solar cells as a new high efficient solar cell have been paid much more attention in the past years is prepared by hydrogenated amorphous silicon films deposited on crystalline silicon. The textured structure in high efficiency heterojunction solar cells reduces the reflection and improves the light trapping. As a result, there is a subsequent higher short circuit current density in the solar cells. Wet chemical etching process is used to obtain texture on monocrystalline silicon substrate. Several key parameters which influence texturing processes, including concentration of isopropyl alcohol, etching time, substrate type and the content of sodium silicate, are selected to optimize and achieve the low reflection on silicon substrate. After that, the reflectance reduces from 34.7% to 9.14% （1011 nm） and the short circuit current density enhances from 32.06 mA/cm-2 to 36.16 mA/cm-2. The textured substrate can effectively improve the performance of SHJ solar cells.