Hydrogen passivation of AlGaAs and GaInP for high efficiency solar cells

Epitaxially grown films of Al/sub 0.25/Ga/sub 0.75/As and Ga/sub 0.5/In/sub 0.5/P were treated in a Kaufman hydrogen ion-beam system to evaluate defect passivation. Films were characterized by measuring the electrochemical I-V profile before and after treatment. After passivation, an increase was observed in short-circuit current for some Al/sub 0.25/Ga/sub 0.75/As films as high as 50%, but there was also deactivation of shallow states. To reactive shallow levels in Al/sub 0.25/Ga/sub 0.75/As, a brief anneal (5-10 min) at 400 to 425 degrees C was adequate. Annealing the Ga/sub 0.5/In/sub 0.5/P films in a phosphine atmosphere at temperatures up to 550 degrees C has been ineffective at restoring the carrier concentration.<>