Laser-Induced Nanostructured Si and SiGe Layers for Enhanced Optical and Thermoelectric Performance

We investigate a method for fabricating layers that exhibit both high optical absorption and promising thermoelectric properties. Using plasma-enhanced chemical vapor deposition (PECVD), amorphous Si and Si₇₂Ge₂₈ layers are deposited on glass substrates and subsequently processed via laser annealing to achieve nanostructured layers. Our results show that a single laser annealing pulse at 40 mJ yields the highest power factor, approximately 90 μW/m·K². Additionally, we observe a maximum absorbance enhancement factor of 60 times in the spectral region near 880 nm for samples treated with a single pulse of 60 mJ compared to untreated samples. The effects of laser energy, the number of pulses, and material choice are further discussed.