Modifying Nanostructure Of Black Multi-crystalline Silicon

Black multi-crystalline Si(Bmc-Si) materials made by metal-catalyzed chemical etching(MCCE) technique have excellent light-trapping ability, but its nanostructured surface will lead to high recombination of carriers. Therefore, the nanostructure has to be modified to improve both light absorption and electric properties of the final solar cells. In this work, an alkali solution post-etching method was mainly investigated to form unique nano-scale pseudo-pyramid texture in mc-Si(Pmc-Si) wafer by adjusting the concentration, temperature and reaction time. Consequently, Pmc-Si solar cell achieved an efficiency ~18.45%, which is ~0.5% higher than that of normal mc-Si and Bmc-Si ones. Besides, the deposition behavior of dual Ag/Cu ions on the silicon wafer was investigated in order to adjust the adhesive amount, size and uniformity, in aim to reduce the Ag consume in the MCCE process; a inverted nano-pyramid texture also can be converted from nano-hole structure on the silicon wafer by using an acid system at room temperature.