Manoj,R; Jayaraj, M K(Department of Physics, October , 2006)
[+]
[-]
Abstract:
Materials exhibiting transparency and electrical conductivity simultaneously,
transparent conductors, Transparent conducting oxides (TCOs), which have
high transparency through the visible spectrum and high electrical
conductivity are already being used in numerous applications. Low-emission
windows that allow visible light through while reflecting the infrared, this
keeps the heat out in summer, or the heat in, in winter. A thin conducting
layer on or in between the glass panes achieves this. Low-emission windows
use mostly F-doped SnO2. Most of these TCO’s are n type semiconductors
and are utilized in a variety of commercial applications, such as flat-panel
displays, photovoltaic devices, and electrochromic windows, in which they
serve as transparent electrodes. Novel functions may be integrated into the
materials since oxides have a variety of elements and crystal structures,
providing great potential for realizing a diverse range of active functions.
However, the application of TCOs has been restricted to transparent
electrodes, notwithstanding the fact that TCOs are n-type semiconductors.
The primary reason is the lack of p-type TCOs, because many of the active
functions in semiconductors originate from the nature of the pn-junction. In
1997, H. Kawazoe et al.[2] reported CuAlO2 thin films as a first p-type TCO
along with a chemical design concept for the exploration of other p-type
TCOs.