160 likes | 892 Views
Motivation . Zinc Oxide (ZnO) is a promising wide bangap semiconductor material Other important properties of ZnO: piezoelectricity biocompatibility easy manufacturing of nanostructures . Motivation . Potential technological applications of ZnO:UV light emitting devices and sensorstransducersbiosensorsZnO thin films and nanostructures can be grown on cheap substrates such as glass Understanding the synthesis and behavior of ZnO materials may enable the deployment of these n9449
E N D
1. Nanoparticle Dynamics During Laser Synthesis of Zinc Oxide Nanocrystals By
Lorenzo Smith
Renato Camata (mentor)
3. Motivation Potential technological applications of ZnO:
UV light emitting devices and sensors
transducers
biosensors
ZnO thin films and nanostructures can be grown on cheap substrates such as glass
Understanding the synthesis and behavior of ZnO materials may enable the deployment of these new technologies.
The combination of laser ablation and aerosol processes provides a good platform for ZnO nanostructure synthesis.
4. Goal The goal of this project is to investigate the behavior of aerosol populations during the synthesis of ZnO nanocrystals by laser ablation. On-line measurements of the aerosol size distributions may help improve control over the synthesis of ZnO nanostructures.
5. Schematic of the experimental setup for on-line measurements of aerosol size distributions
6. Reproducibility Test
7. Log Curve Fitting to Measured Size Distribution
8. Log-Normal Function
9. Log-Normal Size Distributions
10. Effect of Laser Energy Density
11. Processes of Nanoparticle Growth
12. Results Nanoparticle populations exhibit lognormal size distributions with a concentration peak in the 20-25 nm size range.
As the laser energy density is raised the size of particles and their total concentration increases up to 6.25 J/cm2, at which a sudden drop occurs.
13. Conclusion We have been able to monitor the aggregation process of these gas-suspended ZnO nanoparticles.
This may allow better control of laser synthesized ZnO nanostructure films for potential integration into functional systems.
14. ZnO Future There has been much interest in optoelectronics applications to use this material as a UV laser.
Zinc Oxide is a strong candidate for short-wavelength optical devices such as light emitting diodes or laser diodes.
Being considered for antireflection coatings, gas sensors, and photoluminescent devices
15. Acknowledgement
We acknowledge support from the National Science Foundation (NSF)-Research Experiences for Undergraduates (REU)-site award to the University of Alabama at Birmingham (UAB).