A solution based route to GaAs thin films from As(NMe2)3 and GaMe3 for solar cells

Abstract

The novel deposition of GaAs thin films on glass substrates from a solution based route involving the aerosol assisted chemical vapour deposition (AACVD) of As(NMe₂)₃ and GaMe₃ dissolved in toluene is reported. The gallium arsenide films were analysed by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), energy dispersive X-ray (EDX) analysis, X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Powder XRD showed that cubic polycrystalline GaAs had been deposited with films grown at the higher temperatures having a Ga to As ratio of 1 : 1. EDX mapping, XPS depth profiling and SIMS showed that the films contained low levels of contaminants. The method described shows the formation of GaAs films with increasing crystallinity and stoichiometry reaching unity with increasing deposition temperature.