Texturing of monocrystalline silicon wafers by HF-HCl-H2O2 mixtures: Generation of random inverted pyramids and simulation of light trapping in PERC solar cells
| Autor: | Edwin Kroke, Florian Honeit, André Stapf, Christoph Gondek |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Materials science
Silicon Scanning electron microscope chemistry.chemical_element 02 engineering and technology engineering.material 01 natural sciences law.invention Monocrystalline silicon chemistry.chemical_compound Optics Hydrofluoric acid Etching (microfabrication) law 0103 physical sciences Solar cell Wafer 010302 applied physics Renewable Energy Sustainability and the Environment business.industry Diamond 021001 nanoscience & nanotechnology Surfaces Coatings and Films Electronic Optical and Magnetic Materials chemistry engineering Optoelectronics 0210 nano-technology business |
| Zdroj: | Solar Energy Materials and Solar Cells. 159:112-120 |
| ISSN: | 0927-0248 |
| Popis: | Solutions containing hydrofluoric acid (HF), hydrochloric acid (HCl), and hydrogen peroxide (H2O2) were investigated as novel acidic, NOx-free etching mixtures for texturing of monocrystalline silicon wafers. High etch rates of up to 13.3 nm s−1 were observed at room temperature, which are comparable to the etch rates of KOH-IPA solutions. The silicon surface was investigated by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM), indicating pyramidal textures for diamond wire and SiC-slurry sawn as well as saw-damage etched (polished) wafers. Non-stirred baths generate random pyramidal structures while constantly stirred solutions generate novel random inverted pyramidal surface structures. The light trapping efficiency of wafers etched by the HF-HCl-H2O2 solutions was compared by UV/vis-reflectivity measurements to KOH/i-propanol specimens indicating lower reflectivities for the HF-HCl-H2O2-treated samples. Using the ‘wafer ray tracer’ (pvlighthouse.com) the light absorption properties of monomodal and random inverted pyramid structures were simulated and compared to well-known random and monomodal textures for PERC solar cells, clearly indicating the best performance for random inverted pyramids. Besides, simulation of a PERC solar cell on a roof top at our university was performed, indicating improved performance, especially for random inverted pyramid textures. |
| Databáze: | OpenAIRE |
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