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Novel WO3–CuFe2O4 nanocomposites with significantly higher electromagnetic wave absorption properties have been synthesized. The synthesized nanocomposites exhibit coexistence of both phases at higher WO3 concentrations without impurity phases as confirmed by XRD and FTIR studies. TEM micrographs demonstrate the formation of CuFe2O4 nanoparticles embedded in WO3 shells. FTIR results reveal the presence of characteristic stretching and vibration modes associated with WO3 and CuFe2O4. The magnetic measurements show the ferromagnetic behavior of all studied samples. However the saturation magnetization has shown a decreasing behavior while coercivity increases with the concentration of incorporated WO3. The WO3 concentration up to 30 wt% enhances the microwaves absorption properties (−26.32 dB at frequency 6.6 GHz) and shifts the absorption maximum curve to higher frequency.

Ternary chalcopyrite-like compound of CuSbSe2 was found to be an excellent agent to assist the reactive sintering of CuInSe2 (CIS) from Cu2Se and In2Se3 at lower temperature, which is the light absorber material in the most promising thin film solar cells. With low melting point and excellent wettability, CuSbSe2 acts as a liquid-phase sintering flux to efficaciously increase atomic diffusion rate during the sintering process, and furthermore the two raw materials provide chemical driving force. By the intentional introduction of CuSbSe2 doping into CuInSe2, the well-crystallized ceramic samples can be perfectly sintered at 500 °C, without obviously scarifying light absorption at the low doping level (≤0.5 mol%). The XPS analyses were performed to determine the crystal lattice location and valence state of Sb. Similar sintering-promoting effect was also found in the CuSbSe2-doped Cu(In,Ga)Se2 (CIGS) film.

As one of the most promising solutions for the green energy, thin-film photovoltaic cell technology is still immature and far from large-scale industrialization. The major issue is getting low cost and stable module efficiency. To solve these problems, a large amount of advanced solar materials have been developed to improve all parts of solar cell modules. Here, some new solar material developments applied in different critical parts of chalcogenide thin-film photovoltaic cells are reviewed. The main efforts are focused on improving light trapping and antireflection, internal quantum efficiency and collection of photo-generated carriers.

Nanostrcutured particles and polycrystalline thin films of Sn-doped chalcopyrite are synthesized by newly-developed methods. Surprisingly, Sn doping introduces a narrow partially filled intermediate band (IB) located ~1.7 eV (CuGaS(2)) and ~0.8 eV (CuInS(2)) above the valance band maximum in the forbidden band gap. Diffuse reflection spectra and photoluminescence spectra reveal extra absorption and emission spectra induced by the IBs, which are further supported by first-principle calculations. Wide spectrum solar response greatly enhances photocatalysis, photovoltaics, and photo-induced hydrogen production due to the intermediate band.