Comparison of vapor phase and liquid phase epitaxy for deposition of crystalline Si on glass

We compare the suitability of vapor phase and liquid phase epitaxy in a two step deposition process for the formation of thin crystalline Si films on grass substrates. In a first deposition step, we form polycrystalline Si seeding layers on glass. In a second step, we increase the thickness either by vapor phase or liquid phase epitaxy. Liquid phase epitaxy leads to growth of faceted grains of more than 100 mu m in diameter but the films are not continuous. In contrast, chemical vapor deposition results in continuous, smooth films with grain sizes up to 7 mu m. This difference of morphology originates from the influence of supersaturation and growth rate anisotropy. Chemical vapor deposited films exhibit surface morphologies and electrical properties that are promising for the preparation of crystalline thin film Si solar cells.