Andrew Oriani with Kathleen Kash
A Novel Route to Synthesis of Sn3N4 and ZnSnN2 Thin Films
III-Nitride direct band-gap materials have long been used in opto-electronic applications ranging from consumer high density optical storage devices and LED’s to ultraviolet research lasers.1-2 By replacing the group-III sublattice with an II-IV ordered pair sublattice it is possible to create a new class of ternary wide direct band-gap materials collectively known as the II-IV-Nitrides.3 Recent experiments in plasma-assisted vapor-liquid-solid growth have yielded polycrystalline ZnSnN2 and/or competing binary phases, depending on growth conditions.4 An alternative replacement reaction method for synthesis of Sn3N4 and ZnSnN2 involving the annealing of a precursor thin film on glass has been proposed, modeled after successful conversion of a thin film of SnO2 to ZnSnP2.5 The goal of these experiments is to study the controlled conversion of SnO2 thin films to Sn3N4 by exposure to NH3 and alternatively, by exposure to both NH3 and Zn vapors, to ZnSnN2. The effects of substrate temperature, gas composition and pressure, and time, on thin film structure, composition and properties will be investigated via measurements of electron transport, optical properties, chemical analysis and x-ray diffraction spectroscopy.