In this study, Bismuth doped Titanium dioxide thin films were deposited on glass substrates by a pulse laser deposition using laser. The effect of annealing temperature on the structural and electrical properties was ...In this study, Bismuth doped Titanium dioxide thin films were deposited on glass substrates by a pulse laser deposition using laser. The effect of annealing temperature on the structural and electrical properties was investigated. X-ray diffraction pattern for pure and doped titanium dioxide films with different doping different ratio with Bi show that these films have amorphous structure oanvert to polycrystalline structure with annealing and doping and have a good identically with standard peaks for Anatase and Rutile phases. The orientation was at specific direction for Rutile. The crystalline of films increases by the increase of doping ratio. The crystalline increased with annealing temperature. Annealed films at different annealing temperatures have been studied. The results show that these films have two activation energies and by increasing the doping ratio, the activation energies and the conductivity increase. Both the annealing and composition effects on Hall constant, density of electron carders and Hall mobility are studied. Hall Effect measurements show that all films have n- type charge conductivity and the concentration increases while the mobility decreases with doping and annealing.展开更多
First-principles calculations show that the pulse laser induced graphite-to-diamond phase transition is related to the lattice stress generated by the excited carriers,termed as "quantum electronic stress(QES)&qu...First-principles calculations show that the pulse laser induced graphite-to-diamond phase transition is related to the lattice stress generated by the excited carriers,termed as "quantum electronic stress(QES)".We found that the excited carriers in graphite generate a large anisotropic QES that increases linearly with the increasing carrier density.Using the QES as a guiding parameter,structural relaxation spontaneously transforms the graphite phase into the diamond phase,as the QES is reduced and minimized.Our results suggest that the concept of QES can be generally applied as a good measure to characterize the pulse laser induced phase transitions,in analogy to pressure induced phase transitions.展开更多
文摘In this study, Bismuth doped Titanium dioxide thin films were deposited on glass substrates by a pulse laser deposition using laser. The effect of annealing temperature on the structural and electrical properties was investigated. X-ray diffraction pattern for pure and doped titanium dioxide films with different doping different ratio with Bi show that these films have amorphous structure oanvert to polycrystalline structure with annealing and doping and have a good identically with standard peaks for Anatase and Rutile phases. The orientation was at specific direction for Rutile. The crystalline of films increases by the increase of doping ratio. The crystalline increased with annealing temperature. Annealed films at different annealing temperatures have been studied. The results show that these films have two activation energies and by increasing the doping ratio, the activation energies and the conductivity increase. Both the annealing and composition effects on Hall constant, density of electron carders and Hall mobility are studied. Hall Effect measurements show that all films have n- type charge conductivity and the concentration increases while the mobility decreases with doping and annealing.
基金supported by the National Natural Science Foundation of China(Grant No.21603210)Chinese Youth 1000 Talents Program+1 种基金the Fundamental Research Funds for the Central Universitiesthe United States Department of Energy Basic Energy Sciences(Grant No.DE-FG0204ER46148)
文摘First-principles calculations show that the pulse laser induced graphite-to-diamond phase transition is related to the lattice stress generated by the excited carriers,termed as "quantum electronic stress(QES)".We found that the excited carriers in graphite generate a large anisotropic QES that increases linearly with the increasing carrier density.Using the QES as a guiding parameter,structural relaxation spontaneously transforms the graphite phase into the diamond phase,as the QES is reduced and minimized.Our results suggest that the concept of QES can be generally applied as a good measure to characterize the pulse laser induced phase transitions,in analogy to pressure induced phase transitions.
