Phase Separation on GaInAsSb Films for Thermophotovoltaic Devices
Ga0.81In0.19As0.14Sb0.86 layers were grown on (100)-Te doped GaSb substrates 2º missoriented towards (110), (111)A and (111)B directions by metalorganic vapour deposition (MOVPE) at 540 °C. X-ray reciprocal space maps done in symmetric (224) and asymmetric (115) directions show a super-lattice structure due to the phase separation with a 5 nm period and independent of substrate orientation. The x-ray maps show different stage of relaxation of the films and in same cases an interdiffusion region near the substrate. Despite of the phase separation, channelling experiments with H ions as projectiles showed a good quality of the films. Channelling experiments show that the crystalline quality gets worse with increasing the In and As concentration.
Paula Maria Vilarinho
V. Corregidor, N. Franco, E. Alves, N. P. Barradas, "Phase Separation on GaInAsSb Films for Thermophotovoltaic Devices", Materials Science Forum, Vols. 514-516, pp. 447-451, 2006