A couple of companies have highlighted wet chemical texturing processes for PERC cells that avoids using isopropyl alcohol (IPA) that is intended to offer a low-cost alternative for high-efficiency solar cells at EU PVSEC.
Leading wet chemical production tools specialist RENA, in collaboration with imec have developed a novel isopropyl-alcohol (IPA)-free process for the texturing of Cz-Si wafers, dubbed ‘monoTEX F,’ RENA’s next generation texturing additive.
However, US-based Akrion Systems, a well known wet chemical firm from the semiconductor industry is presenting papers, though not exhibiting, covering an IPA-free additive for alkaline texturing.
According to RENA, its monoTEX F is a moderating and wetting agent that is said to behave almost ‘linear’ towards changes in process temperature and alkali concentration, which enables it to operate at temperatures far below its boiling point, negating evaporation and providing a stable concentration of ratios in the etching mixture during the texturing process step.
As a result, monoTEX F simplifies the texturing and widens the texturing process window all at once, while increases the texturing bath lifetime that helps lower overall process costs.
“When applying this novel monoTEX F-based texturing in our Si PV pilot line to process large area (156×156 mm2) PERC-type solar cells, we achieved excellent conversion efficiencies well above 21%,” said Dr. Joachim John, R&D project manager at imec. “We are confident that RENA’s monoTEX® F-based texturing process is an excellent candidate to be considered for next generation high volume Cz-silicon solar cell manufacturing.”
Ismail Kashkoush, Ph.D., Vice President Applications and Technology at Akrion Systems had a poster paper displayed on Monday that highlighted their IPA free solution in an oral presentation entitled “Development of IPA-free Texturing Processes in Advanced Solar Cell Fabrication.”
An oral presentation Tuesday, entitled “Correlation between Conductivity and pH Measurement for KOH Solutions and Additives,” that included co-authors of this work, Adrien Danel of CEA, Le Bourget du Lac, France as well as Dr. Chen, Jennifer Rieker and Dennis Nemeth from Akrion. The paper concluded that the use of proprietary closed loop concentration control significantly reduces rework and wafer miss-processing resulting in robust manufacturing with reduced cost.
RENA and imec are both exhibiting at EU PVSEC.