Gallium antimonide phosphide growth using Halide Vapor Phase Epitaxy

• Published in: Solar energy materials and solar cells 2020-06, Vol.209, p.110440, Article 110440
• Main Authors: Calero-Barney, S.J., Paxton, W., Ortiz, P., Sunkara, M.K.
• Format: Article
• Language: English
• Subjects: Charge transfer; Computer applications; Deposition; Epitaxial growth; Epitaxy; Gallium; Gallium antimonide; Gallium antimonides; Growth rate; Halide vapor phase epitaxy; III-V alloys; Kinetics; Phosphides; Reaction kinetics; Reactor modeling; Reactors; Substrates; Sulfur; Surface charge; Temperature; Thermodynamic equilibrium; Vapor phase epitaxy; Vapor phases; Vapors; Water splitting
• ISSN: 0927-0248; 1879-3398
• DOI: 10.1016/j.solmat.2020.110440

In this study, we used computational and experimental studies to understand a halide vapor phase epitaxy (HVPE) reactor for growing Gallium Antimonide Phosphide (GaSbyP1-y) films. The computational model is developed for an HVPE reactor having one heating zone for precursor formation and a second zone for film deposition. The first zone is assumed to be in thermodynamic equilibrium. The deposition is modeled using a chemistry set describing various gas phase and gas-solid kinetics. As a case study, the growth of the novel GaSbyP1-y alloy was modeled and the effect of different variables i.e. substrate temperature and system pressure were evaluated. The predicted values for the growth rate are in good agreement with the ones obtained experimentally and other important features such as the crystalline quality and degree of Sb incorporation were correlated with the deposition temperature. The type of photoelectrochemical activity confirms the GaSbyP1-y alloys can be used as photoanodes for water splitting and at low applied biases over-perform a sulfur-doped commercial GaP, however, surface charge transfer kinetics need to be optimized. •HVPE model of GaSbP deposition comprised gas-phase and gas-solid kinetics.•Process optimization enhanced the crystallinity and composition of GaSbP alloys.•This work contributes to developing affordable synthesis methods of III-V alloys.•GaSbP over-performs sulfur-doped GaP regarding onset and fill factor of J-V curves.•Photocurrents of GaSbP alloys show good potential for unassisted water splitting.