Epitaxial thickening of AIC poly-Si seed layers on glass by solid phase epitaxy

A novel method for producing high-quality polycrystalline silicon (poly-Si) films on glass by means of solid phase epitaxy (SPE) of evaporated amorphous silicon on aluminium-induced crystallisation (AIC) poly-Si seed layers is introduced. Optical transmission microscope, Raman, UV reflectance spectroscopy and cross-sectional transmission electron microscope measurements show consistently that a transfer of the crystal properties of the AIC poly-Si seed layer into the crystallised amorphous silicon layer has been achieved. A 1-sun open-circuit voltage of 337 mV is realised with a hydrogenated SPE/AIC p-n junction device, which is a promising result considering the early stage of process development. The SPE/AIC method appears well suited for the fabrication of poly-Si thin-film solar cells on glass and, due to the high crystal quality and the much larger average grain size, could lead to improved energy conversion efficiencies compared to Si solar cells made by solid phase crystallisation.