Cd-free buffer layers for CIGS solar cells prepared by a dry process

ZnSe buffer layers for Cu(ln,Ga)Se-2/buffer/ZnO solar cells have been prepa red by metal organic chemical vapor deposition (MOCVD). Using photoassisted MOCVD, deposition temperatures down to 265 degreesC are possible. It is sh own that deposition temperatures well below 300 degreesC are essential as w ell as deposition times not much longer than 3 min. Higher temperatures and longer deposition times lead to absorber degradation. With optimized buffe r deposition efficiencies of 11% have been obtained on CIGS absorbers from the Siemens pilot production line. (C) 2002 Elsevier Science B.V. All right s reserved.