Study of mesoporous silicon nanowires

We report on the structural and optical properties of mesoporous silicon nanowires (PSiNWs) fabricated using silver ions assisted electroless etching method. The strongest photoluminescence signal has been measured from samples etched with 4.8M of HF. Reflectance were measured versus nanowire length and were inferior to 0.1%. Models based on cone shape of nanowires located in circular and rectangular bases were used to calculate the reflectance using the Transfert Matrix Formalism of PSiNWs layer. The modeling of the reflectance permits to explain this value by taking account into the shape of the nanowires and its porosity. Optical absorbance and transmission were also theoretically studied. The absorbance was superior to that obtained with silicon nanowires and the ultimate efficiency was about equal to 25% for normal incidence angle. These results could be applied to the potential application in low-cost and high efficiency PSiNWs based solar cells.