Morphological and spatial control of InP growth using closed-space sublimation

Scalable growth of high quality III-V semiconductor thin films on non-epitaxial substrates is of profound interest for photovoltaic applications. Here, we demonstrate growth of indium phosphide (InP) crystals directly on metal foils using closed-space sublimation (CSS) method. CSS allows effective transfer of source material to the substrate due to a small (∼2 mm gap between source and substrate) sublimation space. The crystallization kinetics are found to be dependent on the substrate temperature and pressure of the system. Importantly, experiments revealed that both InP nanowires and polycrystalline films could be obtained by tuning the growth conditions. Furthermore, utilizing a silicon dioxide mask, selective nucleation of InP on metal substrates was obtained. Photoluminescence measurements depict the high optical quality of the CSS grown InP.