Examination within a Photonic Memory-Based Framework: Al and In Dual-Doped ZnO Thin Film UV Photosensor Devices

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Zinc oxide (ZnO) is a promising semiconductor material for optoelectronic applications.
• Enhancing ZnO's photoresponsive and optoelectronic properties is crucial for device performance.
• Doping is a key strategy to tailor semiconductor characteristics, but optimizing dual-doping effects requires investigation.

Purpose of the Study:

• To investigate the room-temperature enhancement of optoelectronic and photoresponsive performance in ZnO via dual doping with Aluminum (Al) and Indium (In).
• To correlate structural and morphological modifications induced by Al and In doping with improved material characteristics.
• To evaluate the potential of dual-doped ZnO for advanced optoelectronic and photonic memory applications.

Main Methods:

• Synthesis of dual-doped ZnO (Al and In) materials, confirming hexagonal wurtzite phase via structural analysis.
• Microstructural and morphological characterization, including crystallite size and particle thickness measurements.
• Systematic investigation of persistent photoconductivity, photocurrent generation mechanisms, photonic memory effects, and photosensor properties under UV illumination.

Main Results:

• Dual doping with 1.0% Al and 1.0% In reduced crystallite size (to 38.66 nm) and particle thickness (to ~201.6 nm), increasing surface:volume ratio.
• The dual-doped ZnO exhibited an approximately 11-fold increase in photocurrent under UV light compared to undoped ZnO, reaching 2.11 × 10^-4 A.
• The slow decay time (τ₂), indicative of memory capacity, significantly increased from 302.89 s (undoped) to 533.31 s (dual-doped), demonstrating enhanced photonic memory.

Conclusions:

• Dual doping of ZnO with Al and In effectively enhances its optoelectronic and photoresponsive characteristics at room temperature.
• The observed grain refinement and increased surface area contribute to improved sensor performance and photocurrent generation.
• The optimal doping ratio (1.0% Al/1.0% In) shows significant potential for applications in photonic memory devices, including multilevel data storage.