Hydrogen implanted zinc oxide thin films demonstrate increased luminescence.
Information transfer at the speed of light! Sound like science fiction? Not anymore, optoelectronics makes this possible through use of different materials for laser, LED applications. Zinc oxide (ZnO) is one such material creating waves in the field due to its large, and direct band gap. It operates efficiently at high temperatures and offers a cheap alternative to the current GaN thin film devices. Prof. S Chakraborti’s group at IITBNF has demonstrated enhanced luminescence by implanting hydrogen in ZnO thin films.
ZnO has been under research for decades, as it has certain impurities which when controlled can produce light of different colours – violet, blue, green, yellow, orange and red. The fact that these properties can be tapped from few nanometers thin ZnO films has brought it to the forefront in the field of optoelectronics.
The team incorporated hydrogen ions in the film and observed its effect on the emitted photoluminescence (PL) spectrum. They found that hydrogen implantation increases the PL intensity. Bombarding of ions on the surface of the film, during implantation, may cause defects in the film. Fortunately these defects can be corrected by heating the films at high temperatures and then cooling slowly. Prof. S Chakraborti’s team successfully demonstrated that this treatment showed further increase in PL intensity, as compared to pure ZnO films.
- Shruti Karande
Work funded/ supported by: Dept. of Science & Technology (DST) of Government of India (GoI); Department of Information Technology of Government of India; Bhabha Atomic Research Centre; IIT Bombay Nanofabrication Facility (IITBNF).
Published paper: Saurabh Nagar, S.K Gupta, Subhananda Chakrabarti, "Increased photoluminescence of hydrogen-implanted ZnO thin films deposited using a pulsed laser deposition technique" Journal of Luminescence 153 (2014): 307-311