Comparative analysis of phase coherence length in polycrystalline CdO films on two distinct substrates

• Published in: Thin solid films Vol. 800; p. 140423
• Main Authors: Vargas, L.M.B., Bolaños, K., da Silva, M.J., de Castro, S., Peres, M.L., de Godoy, M.P.F.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.07.2024
• Subjects: Cadmium oxide; Negative magnetoresistance; Phase coherence length; Weak localization effect; Negative magnetoresistance; Weak localization effect; Phase coherence length; Cadmium oxide
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2024.140423

•High mobility cadmium oxide samples are achieved using spray-pyrolysis technique.•Quantum interference is observed at low temperatures.•The phase coherence length is independent of substrate nature at low temperatures. The role of substrates in thin film growth encompasses structural and morphological characteristics which, as a consequence, can also affect electronic properties. This article reports studies on the structural, morphological, and magnetotransport properties of Cadmium Oxide (CdO) films grown on two distinct substrates, amorphous glass, and crystalline silicon, by spray pyrolysis technique. The crystallinity of CdO grown on Silicon (CdO/Si) is higher as compared to the CdO grown on glass (CdO/glass), although CdO/Si morphology presents a dome-like surface. In both cases, samples showed exponential behavior in the electrical resistance curves in the temperature ranges between 1.9 K to 300 K and negative magnetoresistance, due to the weak localization effect, for temperatures lower than 110 K. The highest electronic mobility for CdO/Si is attributed to the better crystallinity of the domes. The weak localization effect is correlated by the 3D Kawabata model, fitting the magnetoresistance curves to determine the phase coherence length over a temperature range of 4.2 K to 100 K. Despite the huge differences in the morphological and electrical properties, the linear behavior of temperature-dependent phase coherence length, attributed to the electron-electron interaction in this temperature range, is found to be independent of the employed substrate. This remarkable result indicates the potential application of the low-cost spray pyrolysis technique for producing high-speed photodetectors.