Polycrystalline silicon nanowires (poly-SiNWs) films were successfully prepared by using metal assisted chemical etching of polycrystalline silicon (poly-Si) films. The poly-Si films were prepared by solid-phase crystallization of amorphous silicon (a-Si) deposited by different deposition techniques on different substrates. In the case of the electron beam evaporated a-Si on a quartz substrate, the formation of poly-SiNWs was not observed and the structure was found to be porous silicon. On the other hand, poly-SiNWs successfully formed from poly-Si on a silicon substrate. We also found that deposition techniques for a-Si films affect the formation of poly-SiNWs.
We demonstrate the minority carrier lifetime measurements of polycrystalline silicon nanowires (poly-SiNW) films passivated with aluminum oxide (Al<sub>2</sub>O<sub>3</sub>) deposited by atomic layer deposition (ALD). The poly-SiNW films were prepared by metal-assisted chemical etching of poly-Si films. The poly-Si films were prepared by solid phase crystallization of a-Si films deposited by radio-frequency sputtering on aluminum induced crystallized poly-Si template. The deposition of an ALD-Al<sub>2</sub>O<sub>3</sub> passivation layer and subsequent annealing enabled us to measure effective minority carrier lifetime of the poly-SiNW films. The effective lifetime was found to be 5.76 μs. This result indicates that ALDAl<sub>2</sub>O<sub>3</sub> is beneficial to surface passivation of poly-SiNW films.