Efficient nanostructured quasi-single crystalline silicon solar cells by metal-catalyzed chemical etching

•Efficiency of Qsc-Si cell can be improved by using metal-catalyzed chemical etching technique.•Color difference among sc- and mc-Si grains can be depressed due to excellent light trapping.•Characterizes of Qsc-Si ingot showed wide difference from bottom to top.•Quality of mc-Si grains and the proportion of sc-grains are equally important for the performance of Qsc-Si cells.•A parallel subcell model is proposed to explain and improve Qsc-Si cell's performance.

Seed-assisted cast quasi-single crystalline silicon (Qsc-Si) technique allows the production of efficient, low-cost solar cells. However, most of the Qsc-Si wafers still consist of single- and multi-crystalline silicon grains, which lead to difficulties when attempting to achieve high efficiency by using conventional acid or alkali texture processes. This paper highlights the fact that nano-textured Qsc-Si solar cells can reach efficiencies ranging from 18.4% to 18.9% by using the same metal-catalyzed chemical etching technique, along with a depressed color difference. A parallel sub-cell model is proposed to explain how to enhance the performance of Qsc-Si cells.