Abstracts Book - IMRC 2018

• SC4-P056
CHARACTERIZATION OF N-TYPE CuO OBTAINED BY THERMAL
OXIDATION OF COPPER FOILS
Laura Marcela Hill Pastor 1 , Tomás Díaz 1 , Roman Romano Trujillo 1 , Miguel Galvan 2 , Ramón Peña
Sierra 2
1
Benemerita Universidad Autonoma de Puebla, , Mexico. 2 Cinvestav Zacatenco, , Mexico.
Cupric oxide CuO is a material that exhibits semiconductor behavior and shows
many interesting characteristics useful for solar cells devices such as low
production cost, non-toxicity, abundantly and available, direct band gap, good
mobility values, among others. CuO is naturally a p-type semiconductor since it
contains negatively charged Cu vacancies. CuO can be obtained by different
techniques including thermal oxidation, magnetron sputtering, molecular beam
epitaxy, electrodeposition, among others, and its properties are strongly
dependent on the technique and the parameters of the process which are used
to synthesize the material. A disadvantage of this material is the complexity to
obtain n-type CuO layers by doping. This fact impedes to fabricate
homojunctions p-n to use as solar cells and heterojunctions must be made
instead for such application. Some researchers have reported n-type CuO by
chemical methods, but the results and analysis are inconclusive and
controversial.
In this work a process to obtain n-type CuO samples is reported. CuO samples
were synthesized by thermal oxidation at 1000, 950, 900 and 850°C of copper
sheets and NaCl as dopant. The CuO samples were characterized by X-ray
diffraction, SEM (Scanning Electron Microscopy), Hall techniques and Raman
measurements. The X-ray diffractograms showed two peaks in 2θ= 35.78° and
2θ= 39.21° corresponding to the planes (11-1) and (111) and it was identified as
the monoclinic phase of CuO. The Raman spectra showed the four vibrations
corresponding to CuO in the positions 296 (Ag), 344 (Bg 1 ), 634 (Bg 2 ), and 1200 cm -
1
(multiphonon). Moreover, the films exhibited a n-type conductivity with an
electron concentration of 10 14 cm -3 , high mobility (cm 2 /Vs) and a mean grain size
of 55 µm. Reflectance measurements to determine the band gap was also done.
Keywords: Cupric oxide, thermal oxidation, n-type conductivity
Presenting authors email: laura04762@hotmail.com