Polycrystalline Transparent Al-Doped ZnO Thin Films for Photosensitivity and Optoelectronic Applications
Victor V Petrov1, Irina O Ignatieva2, Maria G Volkova1,2
1Institute of Nanotechnologies, Electronics, and Equipment Engineering, Southern Federal University, Taganrog 347922, Russia.
Nanomaterials (Basel, Switzerland)
|August 26, 2023
Summary
This study synthesized aluminum-doped zinc oxide (Al-doped ZnO) films, finding that increasing aluminum content enhances transparency and reduces response time to light, making them suitable for optoelectronic applications.
Area of Science:
- Materials Science
- Nanotechnology
- Solid-state Physics
Background:
- Transparent conductive oxides (TCOs) are crucial for optoelectronic devices.
- Zinc oxide (ZnO) is a promising TCO material, but its properties can be tuned by doping.
Purpose of the Study:
- To synthesize and characterize thin nanocrystalline transparent Al-doped ZnO films.
- To investigate the effect of aluminum doping concentration on structural, optical, and response time properties.
Main Methods:
- Solid-phase pyrolysis at 700 °C for film synthesis.
- X-ray diffraction (XRD) for crystal structure analysis.
- Scanning and transmission electron microscopy (SEM, TEM) for morphology and nanoparticle size determination.
Main Results:
- Films crystallized in the wurtzite structure with decreasing crystallinity upon Al doping.
- Continuous films with uniform nanoparticles (15-20 nm) were observed.
- Transmittance exceeded 94% (400-1000 nm), with a band gap minimum of 3.26 eV at 1% Al.
- Response time to 400 nm radiation decreased with increasing Al content, reaching 8 s at 10% Al due to a shorter charge carrier lifetime (4 s).
Conclusions:
- Al-doped ZnO films exhibit excellent transparency and tunable optoelectronic properties.
- The Burstein-Moss effect influences the band gap with increasing Al concentration.
- Optimized Al doping enhances radiation response time, indicating potential for photodetector applications.
