(45a) Halide Vapor Phase Epitaxy of III-V Semiconductors on Silicon Substrates

III-V semiconductors have been widely used and studied for different applications due to their outstanding optoelectronic properties such as high mobilities, long carrier lifetimes and tunable bandgaps by compositional control. These characteristics are responsible for the high solar energy conversion efficiency observed in materials such as GaInAs and GaInP. GaSb_yP_1-y grown by Halide Vapor Phase Epitaxy (HVPE) is a ternary alloy that has shown promising results for Solar-to-Hydrogen conversion though water splitting, given its bandgap of 1.7eV with a 6.7at% of antimony incorporation (versus 2.26eV of pure GaP). The HVPE deposition process is very advantageous compared to more traditional synthesis techniques of III-V semiconductors because the halide transport is characterized by high growth rates in the order of hundreds of microns per hour, uses cheap precursors and can be scalable, allowing the obtention of affordable III-V. There are few studies on HVPE modeling and most of them have been validated with GaAs growth, therefore, this study was focused on the modeling of GaSb_yP_1-y HVPE growth using the software Chemkin Pro 18. The modeling approach considered a two-zone chamber where precursor formation and film growth take place separately. Chamber pressure, substrate temperature and V/III ratio effects on the film growth rate, have been studied and successfully validated with experimental values. Finally, the photoelectrochemical activity of the grown films was assessed and correlated with the material properties.