Synthesis of photo-responsive indium selenides (InSe and In2Se3) from tris(4,6-dimethyl-2-pyrimidylselenolato)indium(iii) as a molecular precursor

Abstract

Indium selenides (InSe and In₂Se₃) have garnered enormous interest owing to their favourable carrier mobility and high photoresponsivities, exhibiting great application potential in high performance photovoltaic and optoelectronic devices. Selective synthesis of InSe and In₂Se₃ materials from the same molecular precursor is a challenging task. In this study, we prepared and characterized an air and moisture stable tris(4,6-dimethyl-2-pyrimidylselenolato)indium(III) complex, as a single source molecular precursor, to synthesize stoichiometric indium selenides (InSe and In₂Se₃) in the nano-regime with precise control, through proper choice of the reaction solvents. The crystal structure, phase purity and composition of the materials were determined by pXRD and EDS analysis, whereas the electron microscopic studies revealed that the reaction conditions have a profound effect on the morphology of the nanostructures. The UV-DRS analysis showed a blue shift relative to the bulk band gap and falls in the range suitable for solar cell applications. Finally, efficient photoresponsitivity was achieved in the as-prepared cubic InSe and hexagonal In₂Se₃ nanocrystal-based prototype devices.