Controllable nano-texturing of diamond wire sawing polysilicon wafers through low-cost copper catalyzed chemical etching

•A low-cost etching method was proposed for texturing diamond wire sawing polysilicon wafers.•The proposed nano-texturing is highly controllable by adjusting anion in copper salts.•The surface saw marks are removed through copper catalyzed chemical etching.•The resulting inverted pyramid structure shows an outstanding antireflection property. The depressing texturation and stubborn directional saw marks on diamond wire sawing (DWS) polysilicon wafers has resulted in severe limitations for the mass application of DWS technology in PV market. Herein, a simple and low-cost copper-assisted chemical etching method was presented to controllably nano-texturing DWS polysilicon wafers. The work firstly reveals the adjustment of anion species in copper salts can readily control the nanostructure during the copper-catalyzed etching process. After etching, the obtained inverted pyramid structure can effectively reduce the reflectivity of the silicon wafer surface, the reflectance can be as low as 5.8% in the wavelength range of 300–1100 nm. Moreover, the surface saw marks are removed after etching, and the novel texture method guarantee the low recombination rates. The effective texturing method shows a promising potential application in the photovoltaic field.