Barrier height inhomogeneities in InN/GaN heterostructure based Schottky junctions

• Published in: Solid state communications 2011-10, Vol.151 (20), p.1420-1423
• Main Authors: Roul, Basanta, Bhat, Thirumaleshwara N., Kumar, Mahesh, Rajpalke, Mohana K., Sinha, Neeraj, Kalghatgi, A.T., Krupanidhi, S.B.
• Format: Article
• Language: English
• Subjects: A. Heterostructures; C. Schottky junctions; Condensed matter: electronic structure, electrical, magnetic, and optical properties; D. Thermionic emission; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Physics; Surface double layers, schottky barriers, and work functions
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2011.07.008

The electrical transport properties of InN/GaN heterostructure based Schottky junctions were studied over a wide temperature range of 200–500 K. The barrier height and the ideality factor were calculated from current–voltage ( I – V ) characteristics based on thermionic emission (TE), and found to be temperature dependent. The barrier height was found to increase and the ideality factor to decrease with increasing temperature. The observed temperature dependence of the barrier height indicates that the Schottky barrier height is inhomogeneous in nature at the heterostructure interface. Such inhomogeneous behavior was modeled by assuming the existence of a Gaussian distribution of barrier heights at the heterostructure interface. ► InN thin films were grown on GaN templates by PAMBE. ► The transport properties of InN/GaN Schottky junctions were studied. ► The barrier height and the ideality factor were found to be temperature dependent. ► Inhomogeneity of the barrier at the heterostructure interface is observed. ► The inhomogeneous behavior is explained with a Gaussian distribution of barrier heights.