Investigation of Optical Properties of Zinc Oxide Photodetector
Student: Tyler Chism
Degree: M.S., May 2016
Major Professor: Dr. Ryan Tian
Research Area(s):
Photonics
Background/Relevance
- Metal oxide nanostructures are useful for solar cell optimization and light detection devices.
- ZnO is a great candidate for such devices as it is cheap and safe.
- It is easy to grow many different structures of ZnO at nanoscale with highly tunable properties.
Innovation
- Use ZnO sparsely coated 3D nanobranched tree like structures on interdigitated electrode on quartz substrate to make UV photodetector.
- Measure changes in absorbance with variable electric and magnetic field, as well as other variables.
Approach
- Deposit gold in an interdigitated pattern on quartz substrate.
- Grow sparsely coated ZnO nanobranched structures on substrate.
- Attach wires to create photodetector.
- Use electrochemical station to apply biased voltage across device and measure current through device under dark conditions and with light source.
- Place solar cell behind device to measure the light that is transmitted through device.
Key Results
- As voltage across device increased, the transmittance of light through the device seemed to decrease.
- Other variable such as an intensity & wavelength of light as well as varying the rate of voltage sweep seemed to change the absorbance of the device.
Conclusions
- The interaction of light with matter seems to hold more mysteries than previously thought.
- Absorbance of semiconductors such as zinc oxide can possibly be tuned by an applied voltage and other variables.
- Changing light absorbance and transmittance can open the door for new devices and even new physics.
Future Work
- Come to an understanding of the mechanism at work.
- Investigate phenomena so as to apply it to creating new devices and develop new physics.