InP thin films with single-crystalline-like properties on flexible metal substrates for photovoltaic application

We demonstrate heteroepitaxial growth of single-crystalline-like InP thin films by metal organic chemical vapor deposition (MOCVD) on low-cost flexible metal foils. The epitaxy was enabled by a multilayer oxide buffer made using ion beam assisted deposition (IBAD). The InP films were biaxially textured with sharp in-plane texture and exhibited strong (002) preferential out-of-plane orientation. Strong room-temperature photoluminescence was also observed with band gap of ~ 1.27 eV. Electron mobility of > 700 cm2/V-s at a carrier concentration of 5 × 1017 cm-3 was obtained. High quality single crystalline-like InP films on low-cost metal substrates may potentially be used in the fabrication of inexpensive flexible InP solar cells.