Work

Surface Quality Optimisation of Monocrystalline and Polycrystalline Silicon Wafers through Cleaning, Etching and Texturisation Processes for Si Solar Cell Applications

Year: 2025
Type: article
Abstract: Silicon (Si) wafers, critical substrates for semiconductor and photovoltaic (PV) device fabrication, require surface cleaning and damage removal to ensure high-quality performance. This study investigates the surface morphology and contamination levels of monocrystalline silicon (c-Si) and multicrystalline silicon (mc-Si) wafers before and after cleaning. Scanning electron microscopy (SEM) and Energy-dispersive X-ray (EDX) analysis revealed that, before cleaning, both wafer types exhibit micro-roughness and contain contaminants such as iron (Fe), oxygen (O), nitrogen (N), carbon (C) and fluorine (F). For the as-cut c-Si wafer, EDX data reveals a Si content of 85.08%, with contamination levels of C (9.38%), O (2.41%), N (1.45%) and F (0.68%). In mc-Si wafers, slicing introduces surface roughness and leaves residues, with the surface characterised by particulates and metallic contaminants. Following the damage removal process using nitric acid/hydrofluoric acid (HNO₃/HF) etching, the contamination levels on mc-Si wafers reduce significantly, with Si content increasing to 90.8%. In comparison, C decreases to 7.5%, and O drops to 1.7%. The wet-chemical etching removes ~5 µm–12 µm of wafer thickness, effectively eliminating surface defects and contaminants. The cleaning process reduces particulate contamination by over 90%, and a smooth, defect-free surface is observed in SEM images post-cleaning. These results demonstrate that adequate cleaning and damage removal are essential for improving solar cell efficiency by enhancing carrier lifetime, reducing surface recombination, and minimising leakage currents.
Language: English
Open Access status: diamond
OpenAlex ID: W4414143352
FWCI: 0.693
Cites:
Cited by: 3
Related to: 10