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In the paper, SnOx thin films were deposited by reactive magnetron sputtering from a tin target in O2 containing working gas. The evolution from Sn-containing SnO to tetravalent SnO2 films was investigated. The films could be classified into three groups according to their optical band gaps, which are Eg 3.7 eV. The electric measurements show that high conductivity can be obtained much easier in SnO2 than in SnO films. A high electron mobility of 15.7 cm2 V−1 s−1, a carrier concentration of 1.43×1020 cm−3 and a resistivity of 2.8×10−3 Ω cm have been achieved in amorphous SnO2 films. Films with the optical band gap of 3.0–3.3 eV remain amorphous though the substrate temperature is as high as 300 °C, which implies that °btaining high mobility in p-type SnO is more challenging in contrast to n-type SnO2 films.

In the work, Cu 2 O films were prepared by middle frequency (mf) magnetron sputtering and subsequent anneals. CuO phase has been detected in a few Cu 2 O samples and its influences have been examined. The results show that the CuO phase can lead to a decrease of Hall mobility and change the surface morphology of the Cu 2 O films. The highest hall mobility of 43 cm 2 V −1 s −1 with the optical band gaps of about 2.5 eV has been achieved in the Cu 2 O films where CuO is absent, which demonstrates the potential to fabricate high field-effected mobility Cu 2 O-based devices through this method.

High density Cu(In 1-X Ga X )Se 2 (CIGS) quaternary ceramic targets were prepared by hot-pressing sintering from CIGS and Se mixed powders. Influences of Se contents and sintering temperatures on the densities, compositions, structures and morphologies of the CIGS targets were investigated. The results show that the structure of the targets after sintering was single chalcopyrite, and the concentration of Se was higher than 50 at%. CIGS thin films were fabricated by magnetron sputtering followed by an annealing process in N 2 instead of toxic H 2 Se. CIGS films with a Se-rich concentration and appropriate electrical properties for fabricating CIGS solar cells were achieved after annealing.

In this work, we report the fabrication method of sputtering from a CIGS quaternary target to obtain high-efficiency CIGS thin-film solar-cell devices. The as-deposited CIGS absorbers are prepared by sputtering from a CIGS target and a subsequent annealing treatment under the Ar + H2Se (5% H2Se) atmosphere is applied on the absorbers. A high conversion efficiency of 16.7% is achieved with an average conversion efficiency of 15.9% over 10 cm × 10 cm on soda-lime glass. This result shows sputtering directly from a quaternary CIGS target is a very promising fabrication method to obtain high-performance solar-cell devices and is suitable for the further fabrication of large-area devices and modules. J–V characteristic curve of the CIGS solar cell with the best efficiency achieved by sputtering from a quaternary target.

In this paper, we prepared the CIGS thin films with various [Cu]/[In + Ga] ratios by selenization of Cu0.8Ga0.2 and In2Se3 precursor films. The properties of Cu(In,Ga)Se2 film and related solar cell were investigated. Raman spectra confirm that the secondary Cu2−xSe phase tends to segregate at film surface. SEM results show that the grain-size improves noticeably with the increase of the [Cu]/[In + Ga] ratios. For Cu-rich CIGS films, the performances of the related solar cells were damaged greatly and good photovoltaic characteristics cannot be obtained. For near-stoichiometric and Cu-poor films, the mean conversion efficiency close to 10% was achieved over a wide range of composition.

Cu2ZnSnS4 (CZTS) films were fabricated from a ceramic quaternary target, through middle frequency magnetron sputtering. A post sulfurization process was applied for the sputtered films and sulfurization temperatures ranging from 460 °C to 580 °C were utilized. It has been found that obvious Zn loss exists during the sputtering, making the sputtered films become Zn poor although the target is Zn rich. The sputtered films were not totally amorphous, but composed of small CZTS grains at the size of several nanometers. After a post sulfurization process the crystallinity were greatly improved and films composed of densely packed CZTS grains at the size of several hundred nanometers can be obtained at sulfurization temperatures higher than 520 °C. Yet minor SnS coexists with CZTS since the films were Zn poor and Sn rich. And finally the CZTS films sulfurized at 580 °C depict an optical band gap of around 1.55 eV.

Cu–In–Ga precursor thin films were deposited onto soda lime glass by magnetron cosputtering CuIn and CuGa alloy targets. After that, Cu(In,Ga)Se2(CIGSe) absorbers were formed by selenizing those alloy precursors with Se vapor at 550 °C. The influence of the precursor temperature on the properties of CIGSe thin film was investigated. The results show that a lot of pinholes existed in the CIGSe thin film produced by selenizing the Cu–In–Ga alloy precursor, which was sputtering deposited at ambient temperature. After sputtering substrate temperature of 250 °C was applied, pinholes were avoided. The surface roughness of Cu–In–Ga precursor increased with the increase of sputtering substrate temperature. Due to the volume expansion of selenization process, even the precursor with high surface roughness could be converted to smooth and compact CIGSe thin film.

In this work, copper indium gallium selenide (CIGS) absorbers were prepared by sputtering a CIGS quaternary target followed by a subsequent annealing process. The electronic properties and microstructure of the CIGS films with various annealing time were investigated. The various annealing time changes the content of the Cu–Se compounds. A high Cu–Se content leads to a high carrier concentration and a low mobility. An improved efficiency of the solar cell device was found to be highly correlated with the decrease of the Cu–Se content. By decreasing the Cu–Se content, a device with a highest efficiency of 8.63% was achieved in this work.