• 한국표면공학회지
• /
• 제49권3호
• /
• pp.301-306
• /
• 2016

The effects of nanotexturing and post-etching on the reflection and quantum efficiency properties of diamond wire sawn (DWS) multicrystalline silicon (mc-Si) solar cell have been investigated. The chemical solutions, which are acidic etching solution (HF-$HNO_3$), metal assisted chemical etching (MAC etch) solutions ($AgNO_3$-HF-DI, HF-$H_2O_2$-DI) and post-etching solution (diluted KOH at $80^{\circ}C$), were used for micro- and nano-texturing at the surface of diamond wire sawn (DWS) mc-Si wafer. Experiments were performed with various post-etching time conditions in order to determine the optimized etching condition for solar cell. The reflectance of mc-Si wafer texturing with acidic etching solution showed a very high reflectance value of about 30% (w/o anti-reflection coating), which indicates the insufficient light absorption for solar cell. The formation of nano-texture on the surface of mc-Si contributed to the enhancement of light absorption. Also, post-etching time condition of 240 s was found adequate to the nano-texturing of mc-Si due to its high external quantum efficiency of about 30% at short wavelengths and high short circuit current density ($J_{sc}$) of $35.4mA/cm^2$.

• 한국결정성장학회지
• /
• 제23권3호
• /
• pp.119-123
• /
• 2013

Most of the world's solar cells in photovoltaic industry are currently fabricated using crystalline silicon. Czochralski-grown silicon crystals are more expensive than multicrystalline silicon crystals. The future of solar-grade Czochralski-grown silicon crystals crucially depends on whether it is usable for the mass-production of high-efficiency solar cells or not. It is generally believed that the main obstacle for making solar-grade Czochralski-grown silicon crystals a perfect high-efficiency solar cell material is presently light-induced degradation problem. In this work, the substitution of boron with gallium in p-type silicon single crystal is studied as an alternative to reduce the extent of lifetime degradation. The diamond-wire sawing technology is employed to slice the silicon ingot. In this paper, the quality of the diamond wire-sawn gallium-doped silicon wafers is studied from the chemical, electrical and structural points of view. It is found that the characteristic of gallium-doped silicon wafers including texturing behavior and surface metallic impurities are same as that of conventional boron-doped Czochralski crystals.