Resistive switching behavior and multiple transmittance states in solution-processed tungsten oxide.

Area of Science:

• Materials Science
• Nanotechnology
• Electrochemistry

Background:

• Tungsten oxide (WO(x)) films are explored for their electrochromic (EC) and resistive random-access memory (RRAM) properties.
• Solution-processed materials offer scalable fabrication routes for advanced electronic devices.

Purpose of the Study:

• To develop a WO(x) film using a thiourea-assisted solution process.
• To fabricate and characterize a device integrating EC and RRAM functionalities.
• To investigate the structural and electrical properties of the fabricated device.

Main Methods:

• Thiourea-assisted solution process for WO(x) film preparation.
• Fabrication of a stacked EC/RRAM device structure (FTO/WO(x)/electrolyte/ITO and Al/WO(x)/FTO).
• Analysis using transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS).
• Electrical characterization of electrochromic and resistive switching behaviors.

Main Results:

• The WO(x) film contains nanosize pores and metallic-tungsten nanoclusters.
• The EC unit exhibits multiple transmittance states upon voltage application due to Li ion intercalation.
• The Al/WO(x)/FTO RRAM unit demonstrates bipolar nonvolatile resistive switching with a high ON/OFF current ratio (1 × 10(4)).

Conclusions:

• The thiourea-assisted solution process yields a WO(x) film suitable for integrated optoelectronic devices.
• The fabricated device successfully integrates electrochromic and resistive switching functionalities.
• The study highlights the potential of WO(x) for multi-functional memory and display applications.