Progress in Apollo® technology

This paper describes the work performed at BP Solar in Fairfield California on scaling its Apoll®, CdTe technology from 0.09m² to 0.94 m². The paper highlights the efforts and progress in CdS window layer optimization and characterization of CdTe layer, which enabled BP Solar to maintain a high quality device on very large substrates. The effect of tin oxide sheet resistance, CdS absorption, and CdTe grain size are all discussed. Through this work, the aperture area efficiency increased from approximately 6% to 11%. Also, BP Solar set up two beta sites in order to test the outdoor performance of the modules. BP Solar performed internal light soaking and worked closely with IEC (UOD) where cells were stressed under extreme conditions.