Room temperature ammonia sensing performances of pure and Sn doped β-Ga2O3

Abstract

Sn, being an excellent donor, has been doped into β-Ga2O3 lattice through hydrothermal method at 2 mol% and 4 mol% concentrations. Prior to this, Sn is primarily doped into Gallium.Oxy Hydrate (GaOOH) which is then thermally treated and transformed into β-Ga2O3. The obtained samples were characterized by TGA, XRD, SEM, EDAX, TEM, XPS, UV–Visible spectroscopy and BET surface analysis to assess their structural, morphological, optical and surface properties. Pure and Sn doped samples were used for room temperature NH3 vapour sensing. Among all samples, 2 mol% Sn doped sample showed enhanced sensing capability due to its prosperous materialistic properties attained through optimum doping into host material. Humidity dependent sensing studies have been done for 2 mol% Sn doped β-Ga2O3. Humidity mediated and oxygen mediated sensing mechanisms along with chemical & electronic sensitization effects of Sn in favor of enhanced room temperature NH3 sensing have been proposed. Short-term stability studies at room temperature have been performed on 2 mol% Sn doped β-Ga2O3 at 200 ppm of NH3 exposure for a period of 10 consecutive days and found with good stability.