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ZnO microrods (whiskers) were fabricated by a simple thermal oxidation method. The morphologies of the samples were detected by the scanning electron microscope, which showed the ZnO microrods were about 30 μm long with a diameter of 1–2 μm. In the photoluminescence (PL) spectra, only the exciton related emission bands in the ultraviolet region could be obtained at room temperature. And, a new emission band due to the exciton–exciton collision process was observed at the low energy side of the free exciton emission under the excitation intensity of 2.1 kW/cm2. This emission band increased nonlinearly. When the excitation intensity was increased above 16 kW/cm2 some fine structures could also be seen clearly in the PL spectra. These fine structures originated from the cavity modes of the Fabry–Perot etalon.

The photoluminescence properties of MgxZn1−xO alloy thin films fabricated by the sol-gel deposition method were studied. The Mg2+ content in the films was up to 0.36 and they had the ZnO wurtzite structure. The band gap of the films can be controlled between 3.40 and 3.93 eV by adjusting the Mg2+ proportions. Transmittance spectroscopy was used to characterize the excitonic structure of the alloys, which the excitonic character is clearly visible at room temperature. The intense ultraviolet photoluminescence was observed at room temperature. This emission is indicative of the excitonic nature of the material.

Large size monolayer Molybdenum disulphide (MoS2) was successfully grown by chemical vapor deposition method under an atmospheric pressure. The electrical transport properties of the fabricated back-gate monolayer MoS2 field effect transistors (FETs) were investigated under low temperatures; a peak field effect mobility of 59 cm2V−1s−1 was achieved. With the assist of Raman measurement under low temperature, this work identified the mobility limiting factor for the monolayer MoS2 FETs: homopolar phonon scattering under low temperature and electron-polar optical phonon scattering at room temperature.

The influence of A-site size and disorder on metamagnetic transformation in polycrystalline Pr0.5−xLaxCa0.5MnO3 and Pr0.5Ca0.5−xBaxMnO3 at low temperature has been systematically investigated. The introduction of larger A-site cations such as La3+ or Ba2+ will locally suppress the lattice distortion. This “counterdistortion” effect becomes more pronounced with the increase in the A-site average ionic radius ⟨rA⟩, which is favorable to ferromagnetism. Thus the critical field HC1 corresponding to the first sharp metamagnetic step will decrease, and the field-induced magnetization M5 T will increase. However, the A-site ionic radii variance σ2 will dramatically increase when more barium is introduced and a spin glasslike state is induced, which is unfavorable to the stability of ferromagnetism state. Therefore, HC1 will increase and M5 T will decrease. Moreover, the evolution of resistivity at low temperature with σ2 exhibits strong correlation with that of magnetic properties.