Impact of annealing temperature on physical properties of transparent conductive MoO3/Ag/MoO3 trilayer films grown by sputtering

Abstract

In this work MoO₃/Ag/MoO₃ (MAM) trilayer films were successfully deposited onto quartz substrates using RF and DC magnetron sputtering. Following deposition, the samples were annealed at 300 °C, 400 °C, and 500 °C for 2 h in an electric furnace. X-ray diffraction (XRD) was employed to characterize the crystallographic structure. The results showed that the as-deposited film and the sample annealed at 300 °C were amorphous, while the crystalline orthorhombic (α-MoO₃) structure emerged at annealing temperatures of 400 °C and 500 °C. Atomic force microscopy (AFM) measurements were also performed to analyze the surface roughness of the films. In addition, field-emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy (EDX) were utilized to further analyze the surface morphology and elemental composition of the films. X-ray photoelectron spectroscopy (XPS) confirms the existence of Mo, O and Ag on the surface of both the as-deposited and annealed samples. The sheet resistance was measured using a four-point probe, and optical transmittance was evaluated via UV–Visible spectroscopy. Additionally, the variation in optical and electrical properties with annealing temperature was analyzed. The film annealed at 400 °C exhibited the optimal optoelectronic performance, with an improved figure of merit (FOM) of 6.10 × 10⁻² Ω⁻¹. This work provides an effective method to prepared MoO₃/Ag/MoO₃ trilayer transparent conductive films that potential application in optoelectronic devices especially in thin film solar cells.