Persistent Photoconductivity Studies in Nanostructured ZnO UV Sensors
Shiva Hullavarad1, Nilima Hullavarad, David Look
1Office of Electronic Miniaturization, University of Alaska, Fairbanks, AK, 99701, USA. shiva.h@alaska.edu.
Nanoscale Research Letters
|July 24, 2010
Summary
Persistent photoconductivity in nanostructured zinc oxide (ZnO) devices is explained by oxygen vacancies. Depleted oxygen conditions reveal this persistent conductivity, crucial for nanoscale electronics.
Area of Science:
- Materials Science
- Nanotechnology
- Solid State Physics
Background:
- Persistent photoconductivity (PPC) is poorly understood, hindering micro and nanoscale device applications.
- Lack of suitable material systems and device configurations limits PPC research.
Purpose of the Study:
- Investigate the origin of persistent photoconductivity.
- Utilize a nanostructured ZnO-based metal-semiconductor-metal photoconductor device.
Main Methods:
- Fabricated nanostructured ZnO (30-65 nm diameter, 5 μm length) metal-semiconductor-metal devices.
- Performed current-voltage measurements with and without UV illumination.
- Varied oxygen levels during measurements.
Main Results:
- Observed a persistent conductivity trend under depleted oxygen conditions.
- Demonstrated the influence of oxygen levels on photoresponse.
- Correlated PPC with specific device configurations.
Conclusions:
- Explained PPC using a theoretical model involving charged anion vacancies.
- Highlighted the role of oxygen vacancies in ZnO nanostructures.
- Provided insights for designing future photoconductive devices.
Keywords:
Nanoscale devicePersistent photoconductivitySemiconducting II–VI materialsUV sensorZinc oxide
