  Copper oxide thin films are deposited on quartz substrates by DC magnetron
sputtering and the effect of deposition temperature on their optoelectronic
properties is examined in detail. Scanning Electron Microscopy (SEM), X-ray
diffraction (XRD) analysis, Raman spectroscopy, UV-Vis spectroscopy, and
four-probe sheet resistance measurements are used to characterize the surface
morphology, structural, optical, and electrical properties respectively.
Deposition is carried out at room temperature and between 200 and 300 {\deg}C.
XRD analysis indicates that the oxide formed is primarily Cu$_2$O and the
absorption spectra show the films have a critical absorption edge at around 300
nm. The sheet resistance gradually decreases with increase in deposition
temperature thereby increasing the conductivity of these thin films. Also
observed is the increase in band gap from 2.20 eV for room temperature
deposition to 2.35 eV at 300 {\deg}C. The optical band gap and the variation of
sheet resistance with temperature shows that the microstructure plays a vital
role in their behavior. These transformation characteristics are of huge
technological importance having variety of applications including transparent
solar cell fabrication.

Materials Science