IISc Researchers Develops Self-Powered UV Photo Detector (Download PDF)

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Indian Institute of Science (IISc) developed a cost-effective, high-performance, self-powered UV photo detector that can be used for the harvesting optical energy for direct self-charging of energy storage devices like supercapacitor.

Self-Powered UV Photo Detector

Self-Powered UV Photo Detector

Self-Powered UV Photo Detector

  • Self-powered UV photo detector can be used for powering electronic devices in the absence of external power source.

Photo Detector

  • Device for detecting and responding to electromagnetic energy, usually light by using the electrical effect of individual photons.

Key Aspects

  • Semiconducting vanadium doped zinc oxide (VZnO) nanoflakes with conducting polymer are used for developing the photodetector.
  • ZnO (zinc oxide) is the base material for UV detection which can be fixed with vanadium to produce photodetectors that are self-powered.
  • Photodetector is used for quick detection of photo signals (in order of milliseconds) even when UV light power is low.

How it Works?

  • ZnO (zinc oxide) doped with vanadium increases surface area of the materials.
  • Creates surface defects within the band gap of ZnO (gap between the conduction and valence bands of ZnO).
  • Catches the UV radiation that falls on the nanoflakes.
  • Microstructure of zinc oxide changes from nanorods to closely-packed nanoflakes. Nanorods are one-dimensional with greater possibility of light reflection from the top surface. On the other hand, Nanoflakes are two-dimensional with greater light perception.
Work of Self-Powered UV Photo Detector

Work of Self-Powered UV Photo Detector

Work of Self-Powered UV Photo Detector

  • When nanoflakes are hydrogenated the current generation capacity is increased to 1,000 nA.

Benefits

  • Nanoflake (VZnO) produces five times more photocurrent, compared with ZnO
  • Generates only 40 nA photocurrent.
  • Hydrogenated nanoflakes exposed to UV light, detect photo signal within milliseconds reducing response time -  00 times faster than conventional UV photo detectors.
  • VZnO nanoflakes structure has 98 percent light harvesting efficiency- higher than the 84 per cent seen in zinc oxide nanorods.
  • Nanoflakes are 80 % porous than nanorods.

- Published/Last Modified on: October 16, 2016

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