Advanced damage-free neutral beam etching technology to texture Si wafer with honeycomb pattern for broadband light trapping in photovoltaics
| Autor: | Mohammad Maksudur Rahman, Hidetaka Takato, Halubai Sekhar, Michio Kondo, Seiji Samukawa, Tomohiro Kubota, Tetsuo Fukuda |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Silicon business.industry chemistry.chemical_element Condensed Matter Physics Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials law.invention chemistry Resist Photovoltaics Etching (microfabrication) law Solar cell Honeycomb Optoelectronics Wafer Texture (crystalline) Electrical and Electronic Engineering business |
| Zdroj: | Journal of Materials Science: Materials in Electronics. 32:27449-27461 |
| ISSN: | 1573-482X 0957-4522 |
| DOI: | 10.1007/s10854-021-07121-9 |
| Popis: | We introduce a new innovative damage-free neutral beam etching (NBE) technique to transfer a honeycomb resist pattern to silicon (Si) wafer (thickness of 180 µm). Front-surface texturing of Si helps to reduce surface reflection and increase light absorption for solar cell applications. NBE was performed with Cl2 and Cl2/ SF6 gases chemistries, and the influence of the etching time on the etching profiles, surface reflection and potential short-circuit densities (p-JSC) was studied. The Si etching rate with pure Cl2 was ~ 5 nm/min and resulted in anisotropic etch profiles and a minimum surface reflection of 15% at 1000 nm, which is too high for practical use. With the introduction of 5% of SF6, the etching rate increased to 30 nm/min, the etching became isotropic (anisotropy of ~ 1), and sloped sidewalls appeared. NBE with Cl2 (95%)/SF6 (5%) produced a sample with an average surface reflection of 3.7% over the wavelength range 300–1000 nm without any antireflection coating. The minimum surface reflection in this case was ~ 1% at 1030 nm and p-JSC was 40.63 mA/cm2. This type of surface pattern is well suited for low-consumption-material (thin), high-efficiency Si solar cells. |
| Databáze: | OpenAIRE |
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