Porous silicon: A material of choice in solar energy harvesting

Abstract

Porous silicon (PSi) has drawn considerable attention as material for solar cell and sensor applications because of its attractive properties like large surface area within a small volume, controllable pore sizes, convenient surface chemistry, and the ability to modulate refractive index as a function of depth. This talk will focus on the fabrication and characterization of PSi and its possible application in solar energy harvesting. A novel structure for hybrid solar cell containing P3HT:PCBM as photoactive material with porous silicon as the anode will be analyzed. The pore dimension was found to play a crucial role on the performance of the hybrid solar cell. When the pore diameter was tuned to a length comparable to the carrier diffusion length of P3HT:PCBM system the photocurrent enjoyed a huge enhancement. In another application, PSi in a heterostructure of Al/c-Si/PSi/α-Fe 2 O 3 as a photoanode in solar water splitting will also be reported. This photoanode increased the photocurrent at all potentials higher than that of bare Fe 2 O 3 , and a significant cathodic potential shift was observed, demonstrating that Al/c-Si/PSi/α-Fe 2 O 3 photoanode could be used as an efficient photocatalyst in solar water splitting with a lower external bias. Altogether it appears that PSi could be a promising material in solar energy harvesting.