UV-assisted synthesis of indium nitride nano and microstructures

Abstract

Indium nitride (InN) has been made the first time by a combined thermal/UV photo-assisted process. Indium oxide (In₂O₃) was reacted with ammonia using two different procedures in which either the ammonia was photolysed or both In₂O₃ and ammonia were photolysed. A wide range of InN structures were made by these procedures that were determined by the reaction conditions (time, temperature). The reaction of In₂O₃ with photolysed NH₃ gave InN rod-like structures that were made of stacked cones (6 h/750 °C) or discs (6 h/800 °C) and that contained some In₂O₃ residue. In contrast, photolysis of both In₂O₃ and NH₃ gave InN nanowires and pure InN nanotubes filled with In metal (>90%). The transformation of the 3D In₂O₃ particles to the tubular 1D InN was monitored as a function of time (1–4 h) and temperature (700–800 °C); the product formed was very sensitive to temperature. The band gap of the In filled InN nanotubes was found to be 1.89 eV.