Transcript Slide 1

CSMM
Centre for Superconducting and Magnetic Materials
Transparent Conducting Oxides
and Oxide p-n junctions for novel
electronics
Transparent conducting oxides (TCO) thin films are widely used in applications such as
the transparent electrodes of flat panel displays, solar cells and touch panels. A
combination of the p and n types TCO to form a p-n junction can result in qualities ideal
for optoelectronics. Some transparent oxides such as ZnO are also known to be
candidates for diluted magnetic semiconductors, and have potential for applications in
spintronic devices.
A number of materials such as tin-doped indium oxide (ITO), ZnO, and SnO2 are used in
many optoelectronic devices. ITO is currently the most widely used TCO. However, as
indium is a relatively scarce element, the cost for ITO production is high. The other
drawback of ITO films is the lack of chemical stability. The indium of an ITO layer can
diffuse into the organic materials, leading to the degradation of light emitting diode
(LED). In addition the toxic nature of indium could be hazardous to human beings and
the environment.
At present almost all TCO thin films are n-type semiconductors as it is extremely difficult
to fabricate a p-type TCO semiconductor. However, it is crucial to fabricate the p-type in
order to make active circuit components such as diodes in transparent circuits.
This project has three aims:
• The fabrication of p type TCO thin films, such as CuAlO2 and ZnO by pulsed laser
ablation and magnetron sputtering, and study on the physics of the electronic
structure and the optoelectronic properties of the transparent p-type conducting
doped CAO and ZnO thin films.
• The fabrication of TCO p-n junctions, composing of p and n type ZnO thin films on
glass, quartz, ZnO or a-Al2O3 substrates.
• The fabricate of p-n heterostructure junctions composing of p-type colossal
magneto resistance (CMR) thin film with n-type ZnO thin film. This type of junction
could be modulated by external electric and magnetic field.
Recruitment for year 2005 Research Projects