In this paper, the modification of photocatalytic materials or the development of novel photocatalytic materials from four aspects of light absorption, carrier separation, surface reaction and all-weather photocatalysis in this laboratory was summarized, and the applications of photocatalytic materials in organic pollutant degradation, photocatalytic hydrogen and oxygen production and tail gas treatment were discussed. The mechanism of photocatalytic activity enhancement was analyzed based on the energy band theory. In addition, the future development direction of photocatalytic materials was also prospected.

Low-calcium clinker minerals (i.e., ye'elimite, belite and ternesite) have lower calcium content, reduced firing temperature, and decreased CO₂ emission, compared to alite. The development of clinkers primarily composed of these low-calcium minerals represents a significant direction for the sustainable, low-carbon evolution of cementitious materials. This review represented the hydration and performance development of ye'elimite, belite and ternesite, the hydration and performance development of calcium sulfoaluminate cement and belite-ye'elimite-ferrite cement, as well as the preparation, hydration and performance optimization of belite-ye'elimite-ternesite, respectively, with both low-calcium minerals as major minerals. Meanwhile, the effect of gypsum on the low-calcium cement was discussed due to its crucial influence in the hydration of cement clinker. This review could provide a reference for the synthesis of low-calcium clinkers primarily using ye'elimite, belite and ternesite.

Dynamic dimming glazing can adjust the luminous flux of the target spectral band selectively according to the climate change, thus having a good capability for light and heat management, which has attracted increasing attention in building energy conservation. Dynamic dimming glazing for multi-band (i.e., visible light, near-infrared light, and long-wave infrared light) modulation has a greater energy-saving potential due to its more efficient spectral utilization. This review mainly represented the multi-band modulation of the dynamic dimming glazing. The effect of spectral modulation on energy efficiency was discussed, and the related technologies for multi-band modulation were demonstrated. Meanwhile, some challenges in the industrialization of this energy-efficient glazing were analyzed. In addition, the future development trends were also described in accordance with the recent cutting-edge technologies.

In recent years, low dimensional organic-inorganic hybrid copper(I) halides have a great potential in the fields of photoelectric and radiation detection applications due to their high fluorescence quantum efficiency, excellent stability, and low-cost processing feasibility. We prepared a zero dimensional (0D) (TPA)CuI₂ (TPA=tetrapropylammonium, C₁₂H₂₈N⁺) single crystal scintillator by a simple solution evaporation method, and investigate its optical and scintillation properties. (TPA)CuI₂ crystal has a high thermal stability and an air stability. Under UV excitation, it exhibits an ultra-broadband white light emission with a full width at half-maximum (FWHM) of 291 nm and a photoluminescence quantum yield (PLQY) of 62%. Under X-ray excitation, it has an intense radioluminescence, a low afterglow and a decent detection limit, which can be regarded as a novel X-ray scintillator.

Yttrium aluminium garnet (YAG) crystals have applications in optoelectronics, and the defect control of crystal growth is a bottleneck problem to be solved. In this work, the dislocation etch pit morphology and density distribution were investigated in YAG crystal grown by the Czochralski method with and without necking technology, and the YAG crystal samples were polished and etched with phosphoric acid. The dislocation etch pits were photographed by a metalphase microscope. The results show that the dislocation density of YAG crystal is the maximum in the initial shoulder part and the minimum in the cylinder part, as well as a little greater at the end part. The dislocation density in necking end is reduced. In addition, the YAG dislocation etch pit of different crystal directions was analyzed, and the surface energy of each YAG crystal surface was calculated, indicating that the relatively stable plane of YAG etch pit is (110) and (112). Based on the analysis by the stereographic projection, the lattice plane stability of (110) and (112) and their position relation to other lattice planes are the important reasons for the formation of etch pit morphology.

KDP crystal is a nonlinear optical material that is used in inertial confinement nuclear fusion devices. However, the defects seriously reduce the optical performance such as light absorption and laser damage threshold of KDP crystals. It is thus of great significance to investigate the influence mechanism of KDP crystal defects on its electronic structure and optical properties for the improvement of its optical properties. In this paper, the structure, stability and electronic structure of hydrogen and oxygen vacancy defects (i.e., V_H and V_O) on the growth surfaces (100) and (101) of KDP crystals were investigated by using the first-principle calculation. The effect and microscopic mechanism of acidic environment on the structure and properties of surface defects were also discussed. The results indicate that the V_H and V_O defects both are easier to be formed on the surfaces (100) and (101) rather than in bulk KDP crystal. The surface (100) has an intense tolerance for surface V_H and V_O defects, while V_O on the surface (101) prefers to lose electrons, and introduces a deep defect level in the band gap, thusdamagingthe optical properties of the KDP crystal. In addition, acidic environment canlead to more V_O defects on the surface (100) and introduce the defect level in the band gap. Also, acidic environment is conducive to the repair of the V_H defects on the surfaces, and can eliminate the defect states introduced by the surface V_O defects on the surface (101), which is conducive to improving the quality and optical quality of the crystal surfaces.

There are abundant defect structures in lithium niobate crystals, mainly including V_Li, Nb_Li⁴⁺, V_Nb and V_O point defects. The existence of defects greatly affects the properties of lithium niobate crystal(i.e., piezoelectric, electro-optic, ferroelectric, photorefractive, nonlinear optical properties and laser damage threshold) as well as the performance of SAW, electro-optic modulator, acousto-optic modulator, temperature/pressure/acceleration sensor and other devices. The main process of defect formation in lithium niobate crystal can be attributed to the evolution of mesoscale clusters centered on O^2- ions. It is thusimportant to understand the evolution mechanism of mesoscale clusters in the defect formation process of lithium niobate crystal for defect control. This paper was to investigate the dynamic evolution process and formation mechanism of defects in lithium niobate crystal from the aspects of defect types, formation energy and mesoscale cluster model. The hybridization and rehybridization process caused by defects in lithium niobate crystal structure was analyzed, and the coupling of multiple degrees of freedom was considered, which contributes to the defect control, rapid growth and performance control of lithium niobate crystal. In addition, the correlation between the defects of lithium niobate crystal and its properties as well asfunctions was also analyzed.

As one kind of semiconductor material with the superiorperformance, single crystal diamond (SCD) has broad application prospects in power devices, deep space exploration and other fields. However, SCD prepared via microwave plasma chemical vapor deposition (MPCVD) usually contains defects, especially dislocations, seriously restrictingits electrical performance. Lateral epitaxial growth as a common defect control method in semiconductor materialsis used in SCD preparation in recent years. In this work, firstly, a pattern array was constructed on SCD seed by metal catalyzed plasma etching to create a lateral growth condition for the preparation of homogeneous epitaxial. Secondly, SCD layer was prepared by MPCVD method, and the lateral epitaxial growth process was investigated. The samples were tested by laser confocal microscopy, polarizing microscopy, Raman spectroscopyand defect density measurement. The results show that this method can stably and controllably prepare the arrays needed for patterned growth and reduce the defect density of the growth layer.

Aluminum nitride (AlN) is a direct bandgap semiconductor with a ultrawide bandgap width (i.e., 6.2 eV), a high thermal conductivity (i.e., 3.4 W/(cm·K)), a high surface acoustic rate (i.e., V_L=10.97×10⁵ cm/s, V_T=6.2×10⁵ cm/s), a high breakdown field strength as well as stable physical and chemical properties. AIN is an ideal substrate for ultraviolet/deep ultraviolet (DUV) luminescent materials. Al_xGa_1-xN materials made from AlN can achieve a continuous luminescence in a wavelength range of 200-365 nm. AlN crystal as one of developed semiconductor materials with a great potential can be used for high voltage, high temperature and high frequency electronic devices. This review introduced the heteroepitaxial growth principle of AlN single crystal by a physical vapor transport (PVT) method. Recent research progress on the heteroepitaxial growth of AlN on silicon carbide (SiC) substrate was represented based on the corresponding studies on the AlN growth on SiC substrates and the growth of AlN crystals on AlN/SiC substrates and off-orientation SiC substrates. Some challenges and opportunities of growing AlN single crystal on SiC substrate were briefly described, and the future development of AlN materials was prospected as well.