TY - JOUR
T1 - A facile process to prepare copper oxide thin films as solar selective absorbers
AU - Xiao, Xiudi
AU - Miao, Lei
AU - Xu, Gang
AU - Lu, Limei
AU - Su, Zhanmin
AU - Wang, Ning
AU - Tanemura, Sakae
N1 - Funding Information:
The work was funded by the CAS Key Laboratory of Inorganic Coating Materials (No. KLICM-2010-05 ) and CAS Key Laboratory of Renewable Energy and Gas Hydrate (No. KLREGHy007k6 ) and International Cooperation MOST-JST Program Fund (No. 2010DFA61410 ) and National Natural Science Foundation of China (No. 50786108 ).
PY - 2011/10/1
Y1 - 2011/10/1
N2 - Copper oxide thin films as solar selective absorbers were conveniently prepared by one-step chemical conversion method. X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis-NIR spectra and Fourier transform infrared (FTIR) spectra were employed to characterize the composition, structure and optical properties of thin films. The results indicated that the composition, structure and optical properties of thin films were greatly influenced by reaction temperature, time and concentration of NaOH. When reaction temperature was fixed at 40 °C, the as-prepared films consist of pure cubic Cu 2 O. The surface morphology of thin films was changed from square-like structure (reaction time ≤ 25 min) to porous belt-like structure (reaction time ≥ 30 min) with the elongation of reaction time. While for thin films prepared at 60 °C and 80 °C, single Cu 2 O was observed after 5 min reaction. When reaction time is longer than 5 min, CuO appears and the content of CuO is increasing with the elongation of reaction time. With the increase of reaction temperature, the belt-like structure was easily formed for 60 °C/10 min and 80 °C/5 min. Decreasing concentration of NaOH also could result in the formation of CuO and porous belt-like structure. Simultaneously, the film thickness is increasing with the increase of reaction time, temperature and concentration. Films containing CuO with belt-like structure exhibited high absorptance (>0.9), and the emissivity of films increased with elongation of reaction time. Combination of the composition, structure and optical properties, it can be deduced that the porous belt-like structure like as a light trap can greatly enhance absorbance (α), while the composition, thickness and roughness of thin films can greatly influence the emissivity (ε). The highest photo-thermal conversion efficiency was up to 0.86 (α/ε = 0.94/0.08) for thin films prepared at 80 °C/5 min, which proved that the CuO x thin films can be served as high performance solar selective absorbers.
AB - Copper oxide thin films as solar selective absorbers were conveniently prepared by one-step chemical conversion method. X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis-NIR spectra and Fourier transform infrared (FTIR) spectra were employed to characterize the composition, structure and optical properties of thin films. The results indicated that the composition, structure and optical properties of thin films were greatly influenced by reaction temperature, time and concentration of NaOH. When reaction temperature was fixed at 40 °C, the as-prepared films consist of pure cubic Cu 2 O. The surface morphology of thin films was changed from square-like structure (reaction time ≤ 25 min) to porous belt-like structure (reaction time ≥ 30 min) with the elongation of reaction time. While for thin films prepared at 60 °C and 80 °C, single Cu 2 O was observed after 5 min reaction. When reaction time is longer than 5 min, CuO appears and the content of CuO is increasing with the elongation of reaction time. With the increase of reaction temperature, the belt-like structure was easily formed for 60 °C/10 min and 80 °C/5 min. Decreasing concentration of NaOH also could result in the formation of CuO and porous belt-like structure. Simultaneously, the film thickness is increasing with the increase of reaction time, temperature and concentration. Films containing CuO with belt-like structure exhibited high absorptance (>0.9), and the emissivity of films increased with elongation of reaction time. Combination of the composition, structure and optical properties, it can be deduced that the porous belt-like structure like as a light trap can greatly enhance absorbance (α), while the composition, thickness and roughness of thin films can greatly influence the emissivity (ε). The highest photo-thermal conversion efficiency was up to 0.86 (α/ε = 0.94/0.08) for thin films prepared at 80 °C/5 min, which proved that the CuO x thin films can be served as high performance solar selective absorbers.
KW - Absorbance
KW - Copper oxide
KW - Emissivity
KW - Solar selective absorber
UR - http://www.scopus.com/inward/record.url?scp=80052949127&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=80052949127&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2011.07.088
DO - 10.1016/j.apsusc.2011.07.088
M3 - Article
AN - SCOPUS:80052949127
SN - 0169-4332
VL - 257
SP - 10729
EP - 10736
JO - Applied Surface Science
JF - Applied Surface Science
IS - 24
ER -