Liquid phase epitaxial growth of silicon on porous silicon for photovoltaic applications

The aim of this experiment is to grow a thin silicon layer (< 50 mum) by Li quid Phase Epitaxy (LPE) onto porous silicon. This one acts as a sacrificia l layer in order to transfer the 50 mum epitaxial layer onto foreign substr ates like ceramics. After transfer, the silicon wafer is then re-usable. In this work, we used the following procedure the porous silicon formation by HF anodisation on (100) or (111) Si wafers is realised in first step, foll owed by an eventual annealing in H, atmosphere, and finally LPE silicon gro wth with different temperature profiles in order to obtain a silicon layer on the sacrificial porous silicon (p-Si). We observed a pyramidal growth on the surface of the (100) porous silicon but the coalescence was difficult to obtain. However, on a p-Si (111) oriented wafer, homogeneous layers were obtained.