Surface Recombination Processes in Silicon with Nano- Structured Porous Layers Formed by Photocatalysis

Vitaliy P. Kostylyov, Volodymyr V. Chernenko, Olexandr A. Serba, Roman M. Korkishko, Viktor M. Vlasiuk

Abstract: Experimental verification for simultaneous realization of effective antireflection and passivation coating of the back-contact back-junction silicon solar cell (BCBJ SC) front surface by using porous silicon nanostructured layers obtained applying the electrochemical method has been carried out. It has been shown that, using mixed ethanol and concentrated hydrofluoric acid electrolyte on the SC n⁺-surface, the porous silicon film with optimized values of the refractive index and thickness can be grown, which can be reached varying duration of the electrochemical etching process. It has been found that, after formation of the porous silicon film on the n-base BCBJ SC material, the effective surface recombination velocity decreases due to passivation of surface recombination-active centers by hydrogen atoms that are released during the electrochemical reaction, but this effect is unstable because of hydrogen atom desorption from the porous layer.

Keywords: Microporous silicon, electrochemical etching, surface recombination.

Pages: 265 – 271 | Full PDF Paper