The variation of electrical transport properties with thickness for ultrathin indium oxide films

• Published in: physica status solidi (b) Vol. 254; no. 9
• Main Authors: Jiang, Qing‐Kun, Yang, Yang, Zhang, Yu‐Jie, Liu, Xin‐Dian, Li, Zhi‐Qing
• Format: Journal Article
• Language: English
• Published: 01.09.2017
• Subjects: electrical transport; In2O3; Thickness; thin films; transparent conducting oxides; variable‐range hopping
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.201600648

We have systematically investigated the electrical transport properties of a series of In2O3 films (with thickness t ranging from ∼4 to ∼45 nm) grown on yttrium stabilized ZrO2 single crystal substrates. Those t≳11.5nm films reveal metallic characteristics in electrical transport properties, and electron–electron interaction effects govern the low temperature behaviors of the resistivity. For the 6.3 and 3.7 nm thick films, the resistivities variation with temperature [ρ(T)] curves show insulator behaviors in the whole measured temperature range (2–300K). In addition, the two‐dimensional (2D) Mott type variable‐range‐hopping (VRH) dominates the temperature behavior of resistivity in the temperature range Tcross≲T≲80K, and a crossover to the 2D Efros–Shklovskii (ES) VRH occurs below Tcross. Our results are quantitatively consistent with the theoretical predications of the 2D Mott‐VRH and 2D ES‐VRH theories in the corresponding temperature regions.