Mass production of Si quantum dots for commercial c-Si solar cell efficiency improvement

An approach to mass producing Si quantum dots (QDs) based on a controlled chemical etching process is developed. Si ultrafine powders in methanol are oxidized and etched consecutively, followed by sequential filtering. Si QDs thus obtained are well dispersive and uniform in size, and are applied to improving commercial c-Si solar cell performance by depositing Si QD-contained SiO2 sol–gel on the front surface of solar cell. A maximal relative efficiency enhancement of 3.93% is achieved after Si QD concentration optimization, and the photoelectric conversion efficiency increases from 18.05% to 18.76% via photoluminescence conversion of Si QDs.