Germany’s University of Constance, Singapore’s SERIS and the Georgia Tech Research Insitute in the U.S. are all using Schmid’s APCVD solution in developing high efficiency PV cell concepts. Schmid claims that its Atmospheric Pressure Chemical Vapor Deposition (APCVD) process presents certain advantages, in that multiple injection heads in series allow for the source and cap layers to be applied in a single pass. The dopant sources can be harmonized, reports Schmid, allowing co-diffusion to occur in one high-temperature step.
Schmid says that its APCVD tool can achieve a throughput of 4,000 wafers per hour. The wafers are preheated before diffusion.
"Our APCVD systems are very sophisticated and have proven their value in the mass production of IBC [interdigitated back contact] solar cells," said Christian Buchner, the head of Schmid’s solar segment. "Therefore, researchers will certainly find other ways to achieve high efficiency breakthrough cell concepts with this technology."
Schmid reports that more than 100 of its APCVD units are currently in use in mass production for the production of IBC cells.