As-Doped CdSeTe Solar Cells Achieving 22% Efficiency With −0.23%/°C Temperature Coefficient

Since its inception, CdTe-based solar technology has been manufactured by using Cu to dope the absorber and to form effective back contacts. Removing Cu and implementing group V dopants has significantly decreased degradation in accelerated lifetime tests. We demonstrate As-doped cells are now at a crossing point with longstanding Cu-based technology, reaching 22.2%–22.4% efficiency by internal testing and 22.0% certified efficiency. Fill factor and open-circuit voltage on exemplary samples have achieved values as high as 82% or 880–895 mV, respectively. At the same time, the normalized efficiency temperature coefficient is only −0.23%/°C, offering substantively greater energy yield.