Control of Inverted Pyramid Distribution on c-Si Surface via Copper Assisted Chemical Etching and Initial Surface Manipulation
SILICON, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s12633-026-03934-7
- Dergi Adı: SILICON
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Compendex, INSPEC, Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest)
- Orta Doğu Teknik Üniversitesi Adresli: Evet
Özet
Cu-assisted chemical etching (CACE) was employed to form randomly distributed inverted pyramids on crystalline silicon (c-Si) wafers. Critical process parameters, including the concentrations of Cu(NO3)(2) and H2O2, etching duration, and initial wafer surface conditions, were systematically investigated to evaluate their effects on etching kinetics, surface morphology, and optical performance. Reducing the H2O2 concentration promoted the formation of sharper and more uniform inverted pyramids due to enhanced directional etching, whereas lowering the Cu(NO3)(2) concentration suppressed anisotropy and resulted in more rounded surface textures. In addition to etchant optimization, the role of initial surface morphology was examined using as-cut, mirror-polished, and pre-treated wafers. Distinct starting surfaces produced markedly different etched morphologies: DWS (diamond wire-sawn) wafers promoted chain-like alignment of inverted pyramids along defect lines and achieved the lowest average weighted reflectance (similar to 5% over 400-1000 nm), whereas polished wafers yielded more disordered textures with broader size distributions. Furthermore, KOH etching, MACE (metal-assisted chemical etching), and RIE (reactive-ion etching) were employed as pre-treatments to generate diverse surface morphologies prior to CACE, enabling a systematic assessment of how initial surface features govern the resulting surface patterns. The size distribution and directional alignment of the inverted pyramids formed were statistically analyzed. Overall, the results demonstrate that CACE can be effectively tuned through both chemical parameters and initial surface engineering, highlighting its adaptability to a wide range of initial surface conditions for fabricating various light-trapping structures on c-Si.