The comparison of electrical characteristics of Au/n-InP/In and Au/In₂S₃/n-InP/In junctions at room temperature

Highlights: • InP has a major disadvantage of low Schottky barrier height and it is difficult to achieve a Schottky barrier height greater than 0.5 eV, due to the large current for metal–InP substrate at room temperature. • The barrier height of device can be increased by using thin film layer at InP metal–semiconductor junctions. • There has been no report on preparation of Au/In₂S₃/n-InP/In junction by means of spray pyrolysis method in the literature. • This article has been investigated the suitability and possibility of the In₂S₃ thin film for use in barrier modification of n-InP metal–semiconductor devices. • An effective barrier height as 0.543 eV has been achieved for Au/In₂S₃/n-InP/In junction. - Abstract: We fabricated Au/n-InP/In and Au/In₂S₃/n-InP/In junctions and investigated their electrical properties at room temperature. The In₂S₃ thin film has been directly formed on n-type InP substrate with spray pyrolysis method at 200 °C substrate temperature. Detailed structural and optical properties of the film have been investigated by means of scanning electron microscopy (SEM), X-ray diffraction (XRD) and absorption techniques. The band gap energy of In₂S₃ by using spectral data of absorption has been determined to be about 2.80 eV. The values of the ideality factor and barrier height of the Au/n-InP/In and Au/In₂S₃/n-InP/In junctions have been found as n = 1.01, Φ_b = 0.469 eV and n = 1.07, Φ_b = 0.543 eV, respectively. Likewise, the values of barrier height and series resistance of both samples have been obtained from Norde method and they have been calculated as 0.456 eV, 59.081 Ω for Au/n-InP/In junction and 0.518 eV, 101.302 Ω for Au/In₂S₃/n-InP/In junction, respectively