Effect of spraying time on the structural and electrical properties of InAs nanowires

Abstract

Indium arsenide (InAs) nanowire thin films were grown on glass substrates at 250 °C with different thicknesses (50–275 nm) using chemical spray pyrolysis technique. The structural and electrical properties of grown InAs film prepared at different spraying times were investigated. X-ray diffraction pattern confirmed the formation of polycrystalline InAs of hexagonal wurtzite structure with dominant peaks along the (200) plane for film deposited at 2 and 3 min. Hall effect measurements at 300K revealed that the electron mobility decreases as film thickness increases. InAs film with thickness of 55 nm exhibited a minimum electrical conductivity of 10−5 (Ω cm)−1. SEM investigation showed the formation of nanowires for film prepared at 3 min. The variation of the microstructural parameters such as crystallite size, FWMH, lattice constant, and d-value with film thickness was investigated. The experimental results revealed that the crystallite size increased with increase in the thicknesses of the film. EDX measurements and analysis were conducted and showed that the films deposited at 2 and 3 min give good stoichiometric InAs film. AFM data revealed that the average grain size of the film increased from 33 to 66 nm and root mean square of surface roughness of the film was increased from 4.3 to 6.3 nm as spraying time increased from 1 to 3 min.