In this study, we report first-principles calculations of the elastic and thermodynamic properties for CdO in both the B1 (rocksalt) phase and B2 (cesium chloride) phase. The calculations are performed within the framework of density functional theory, using the pseudopotential plane-wave method. From the theoretical results, we find that the high pressure structural phase transition of CdO from B1 structure to B2 structure is 90.31 GPa. The calculated values are, generally speaking, in good agreement with experiments and with similar theoretical calculations. According to the quasi-harmonic Debye model, we investigate the sound velocity and Debye temperature of CdO under pressures in the range of 0 < P < 150 GPa.

All-inorganic perovskite quantum dots (PQDs) have caused extensive research interest because of their excellent optical and electrical properties. However, their water-instability limits their biological applications, and the researches of photoelectrochemical (PEC) biological detection based on CsPbCl3 PQDs are relatively rarely. In this report, the PEC biosensor based on CsPbCl3 QDs modified macroporous TiO2 inverse opal photonic crystals (IOPCs) is designed for alpha fetoprotein (AFP) detection. Firstly, the water stability of PQDs immobilized on IOPCs is remarkably enhanced. In addition, the large specific surface area of TiO2 IOPCs improves the fixed amount of AFP and decreases the electron transmission distance between PQDs and FTO substrate. Ultimately, the PEC biosensor based on TiO2 IOPCs/CsPbCl3 shows excellent detection performance with a low detection limit of 30 pg ml−1 and a good linear range from 0.08 ng ml−1 to 980 ng ml−1 for AFP detection in phosphate buffer saline solutions. This detection system has very extensive application prospect for AFP detection in clinical analysis and biological fields.

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A systematic investigation of rhodium-doped silicon clusters, Rh 2 Si n q with n = 1-10 and q = 0, ±1, in the neutral, anionic, and cationic states is performed using density functional theory approach at B3LYP/GENECP level. According to the optimum Rh 2 Si n q clusters, mostly equilibrium geometries prefer the three-dimensional structures for n = 2-10. When n = 10, one Rh atom in Rh 2 Si 10 0,±1 clusters completely falls into the center of Si frame, and cage-like Rh 2 Si 10 0,±1 geometries are formed. The Rh 2 Si 1,6-9 ? and Rh 2 Si 5,7,9 -clusters significantly deform their corresponding neutral geometries, which are in line with the calculated ionization potential and electron affinity values. The relative stabilities of Rh 2 Si n q clusters for the lowest-energy structures are analyzed on the basis of binding energy, fragmentation energy, second-order energy difference, and HOMO-LUMO gaps. The theoretical results confirm that the Rh 2 Si 6 -, Rh 2 Si 6 , and Rh 2 Si 6 ? clusters are more stable than their neighboring ones. The natural population analysis reveals that the charges in Rh 2 Si n q clusters transfer from the Si atoms to the Rh atoms except Rh 2 Si ? . In addition, the relationship between static polarizability and HOMO-LUMO gaps is discussed.

Perovskite quantum dots (PQDs) are potential luminescent materials for display and LED illumination, whereas CsPbCl3 quantum dots (QDs) exhibit low luminescence quantum yields (QYs), limiting their wide application. In this work, Mn2+ and Eu3+ doped all-inorganic CsPbCl3 QDs were prepared, which were encapsulated into SiO2 film to form ultra-stable and highly luminescent CsPbCl3/SiO2 composites. Through silica coating, surface defects of the composites were reduced effectively, the luminescence QYs of the Eu3+ doped CsPbCl3 PQDs increased from 3.52% to 49.00%, and those of the Mn2+ doped CsPbCl3 PQDs increased from 21.01% to 50.84%. Using these composites, LEDs were prepared, exhibiting good stability and high luminescent efficiency for lighting applications.