Copper Assisted Inverted Pyramids Texturization of Monocrystalline Silicon in a Nitrogen Bubbling Bath for Highly Efficient Light Trapping
Journal
Silicon
Journal Volume
https://www.scopus.com/inward/record.url?eid=2-s2.0-85089978197&partnerID=40&md5=085111b47d5f45a193ed9319117e896e
Journal Issue
2-s2.0-85089978197
Date Issued
2020
Author(s)
Abstract
Inverted pyramid (IP) texturization on silicon wafers has recently attracted attention for the structure’s light trapping ability and low specific surface area. The later property minimizes undesired carrier recombination for solar cells. Wet chemical etching methods based on alkaline and/or acidic etching have been found to be relatively cost effective for creating microscale IPs, and therefore have great potential for mass production. Metal catalytic chemical etching (MCCE) using acidic solutions is known to create these structures in the shortest timespan. In this work, we proposed a simple MCCE IP texturization method for (100) single crystalline silicon (sc-Si) using a Cu(SO4)/HF/H2O2/H2O solution in a bubbling bath. The experiment was performed with different etching times, concentrations of H2O2, and temperatures. As a unique design consideration, our process was conducted with a continuous flow of nitrogen gas bubbles to improve etching uniformity. Under optimized conditions, etching was demonstrated for full size wafers. In checking solution stability, it was found that hydrogen peroxide evaporation occurs throughout the entire process, significantly affecting etching rates and microstructure formation. Therefore, the continuous makeup of H2O2 would be necessary for industrial production.
SDGs
Type
journal article