Interfaces in epitaxially grown Zn3P2 nanowires and their composition dependent optoelectronic properties for photovoltaic applications

Epitaxially grown nanowires have shown promise for photovoltaic applications due to their nanophotonic properties. Moreover, the mechanical properties of nanowires can reduce crystallographic defect formation at interfaces to help enable new material combinations for photovoltaics. One material that stands to benefit from the nanowire morphology is zinc phosphide (Zn3P2), which despite promising optoelectronic properties has experienced limited applicability due to challenges achieving heteroepitaxy, stemming from its large lattice parameter and coefficient of thermal expansion. Herein, we identify the requirements for successful epitaxy of Zn3P2 nanowires using metalorganic chemical vapour deposition and the impact on interface structure and defect formation. Furthermore, using high-throughput optical spectroscopy we were able to demonstrate shifts in the photoluminescence intensity and energy by tuning the V/II ratio during growth, highlighting the compositional tunability of the optoelectronic properties of Zn3P2 nanowires.