Papers by Author: Min Liu

Abstract: Texturization of mono-crystalline by chemical anisotropic etching is one of the most important technologies for modern silicon photovoltaic. IPA is usually added to the alkaline etchants to improve the uniformity of the random pyramid texture due to remove hydrogen bubbles sticking on the silicon wafer by improving the wettability of wafer surface. In this investigation, we carried out a systematic study on the influence of IPA concentrations on the textured surface. The etching experiments were performed on (100) silicon wafer in a mixture of 20 vol. % commercial TMAH solutions (10 wt.%) and IPA (rang from 0~12 vol. %) for etching time ranging from 10 to 70 min at 80°C. The etching mechanism in the TMAH solutions with IPA addition was explained basing on the experimental results and the theoretical considerations.

Abstract: Texturing for mono-crystalline silicon solar cell by chemical anisotropic etching is one of the most important techniques in photovoltaic industry. In recent years, tetramethylammonium hydroxide (TMAH) solution or a mixture of TMAH solution with IPA was reported to be used for random pyramids texturization on silicon surface due to its non-volatile, nontoxic, good anisotropic etching characteristics and uncontaminated metal ions. However, most of the studies were reported about the etching processes by using high TMAH concentration solutions. In this study, a simple and cost-effective approach for texturing mono-crystalline silicon wafers in low TMAH concentration solutions was proposed. Etching was performed on (100) silicon wafers using silicon-dissolved tetramethylammonium hydroxide (TMAH) solutions (0.5~1 %) without addition of surfactant. The surface phenomena, surface morphology and surface reflectance have been analyzed. A textured surface with smaller and smooth pyramids can be realized by using 1 % silicon-dissolved TMAH solutions.