AlGaAs/GaAs DH and InGaP/GaAs DH grown by MOCVD on flexible metal substrates

摘要

High quality, epitaxial, AlGaAs and InGaP thin films have been grown by metal organic chemical vapor deposition (MOCVD) on flexible metal substrates using buffered GaAs on ion-beam textured epitaxial templates. The grown AlGaAs and InGaP films exhibit strong (001) orientation and sharp in-plane texture. We also report preliminary developments on AlGaAs/GaAs and InGaP/GaAs double heterostructures (DH) to measure minority carrier life-time of GaAs thin films grown using MOCVD. Deposition of undoped AlGaAs was done on flexible GaAs/Ge template with a target Al concentration of 10-40 %, at different growth temperatures (650-800 °C) and 20 Torr process pressure. We have observed minority carrier lifetime of greater than 2 ns for GaAs films grown at 650 °C and sandwiched between Al0.2Ga0.8As DH grown at 750 °C. Deposition of lattice matched updoped In0.48Ga0.52P/GaAs is also in progress. Epitaxial AlGaAs and InGaP can be further utilized in the fabrication of flexible low-cost III-V solar cells on metal substrates.