The Phase Evolution and Physical Properties of Binary Copper Oxide Thin Films Prepared by Reactive Magnetron Sputtering

Abstract

P-type binary copper oxide semiconductor films for various O2 flow rates and total pressures (Pt) were prepared using the reactive magnetron sputtering method. Their morphologies and structures were detected by X-ray diffraction, Raman spectrometry, and SEM. A phase diagram with Cu2O, Cu4O3, CuO, and their mixture was established. Moreover, based on Kelvin Probe Force Microscopy (KPFM) and conductive AFM (C-AFM), by measuring the contact potential difference (VCPD) and the field emission property, the work function and the carrier concentration were obtained, which can be used to distinguish the different types of copper oxide states. The band gaps of the Cu2O, Cu4O3, and CuO thin films were observed to be (2.51 ± 0.02) eV, (1.65 ± 0.1) eV, and (1.42 ± 0.01) eV, respectively. The resistivities of Cu2O, Cu4O3, and CuO thin films are (3.7 ± 0.3) × 103 Ω·cm, (1.1 ± 0.3) × 103 Ω·cm, and (1.6 ± 6) × 101 Ω·cm, respectively. All the measured results above are consistent.

Resistive switching in FTO/CuO–Cu 2 O/Au memory devices

“…2 demonstrates the Tauc plot, in which the corresponding bandgap is analysed by extrapolating the linear part of the curve. The obtained indirect bandgap is 1.45 eV that is within the range reported by the authors of [24, 25].…”

Wire Tool Electrode Behavior and Wear under Discharge Pulses

“…Analysis of chemical elements along the line and EDX spectrum of the wire tool at roughing and finishing ( Figure 12) showed mostly chemical elements except for chemical elements of the brass wire in balance-61.8 ÷ 64.3% of Cu and 34.8 ÷ 35.5% of Zn. However, less than 3.4% of oxygen is proof of semiconductive and amphoteric zinc oxide formation, which usually occurs during brass heating (Figure 10a) [92,93], when copper (II) oxide decomposes in the presence of hydrogen [94,95]:…”

The Use of Copper Oxide Thin Films in Gas-Sensing Applications

“…Recently, CuO was modified by Au [22], Fe [23], Li [23,24], Na [24], Pd [25], Pt [26], Px (Piroxicam) [27], Ag [28], Cr [28], Sb [28], and Si [28]. Various techniques have been studied to deposit CuO ( Figure 2), for example: magnetron sputtering [22,[28][29][30][31][32], sol-gel [33], thermal oxidation [14,34], hydrothermal techniques [4,5,15,20,21,[35][36][37], hydrothermal techniques with the electrospinning method [38,39], the spray pyrolysis technique [40], the microwave-assisted method [41], electron beam irradiation [42], microplasma synthesis [43], and successive ionic layer adsorption and reaction (SILAR) [44]. In [28], the author presented M-doped CuO-based thin film deposited using magnetron sputtering technology, which is a typical physical vapor deposition (PVD) technique.…”