37 research outputs found
Application of laser module with driver based on avalanche S-diode for light-emitting diode structure characterization
Conduction mechanism of metal-TiO2-Si structures
The influence of annealing of titanium oxide films on the currents of metal-TiO2-n-Si structures was investigated. It has been shown that regardless of the annealing temperature the conductivity of structures at positive potentials on the gate is determined by currents limited by the space charge in the dielectric with traps exponentially distributed on energy. At negative potentials the main contribution to the current is the thermal generation of charge carriers in the space charge region in the silicon. Interface properties of TiO2-n-Si depend on the structural and phase state of the titanium oxide film which are determined by the annealing temperature
On the effect of ballistic overflow on the temperature dependence of the quantum efficiency of InGaN/GaN multiple quantum well light-emitting diodes
The dependences of the quantum efficiency of InGaN/GaN multiple quantum well light-emitting diodes on the temperature and excitation level are studied. The experiment is performed for two luminescence excitation modes. A comparison of the results obtained during photo- and electroluminescence shows an additional (to the loss associated with Auger recombination) low-temperature loss in the high-density current region. This causes inversion of the temperature dependence of the quantum efficiency at temperatures lower than 220–300 K. Analysis shows that the loss is associated with electron leakage from the light-emitting-diode active region. The experimental data are explained using the ballistic-overflow model. The simulation results are in qualitative agreement with the experimental dependences of the quantum efficiency on temperature and current density
Conduction mechanism of metal-TiO2–Si structures
The conduction model has been proposed for the metal-TiO2–Si (MIS) structures. Rutile films have been prepared on Si substrates by magnetron sputtering of TiO2 target and annealing in the air at temperatures T = 800 and 1050 K. The current-voltage (CVC) and capacitance-voltage characteristics of the structures have been measured over the range of T = 283–363 K. At positive potentials on the gate, the conductivity of the MIS structures is determined by the space charge-limited current in the dielectric layer
Conduction mechanism of metal-TiO2-Si structures
The influence of annealing of titanium oxide films on the currents of metal-TiO2-n-Si structures was investigated. It has been shown that regardless of the annealing temperature the conductivity of structures at positive potentials on the gate is determined by currents limited by the space charge in the dielectric with traps exponentially distributed on energy. At negative potentials the main contribution to the current is the thermal generation of charge carriers in the space charge region in the silicon. Interface properties of TiO2-n-Si depend on the structural and phase state of the titanium oxide film which are determined by the annealing temperature
Diffusion of magnesium in LED structures with InGaN/GaN quantum wells at true growth temperatures 860-980°C of p-GaN
The results of an investigation of Mg diffusion in blue LED structures with InGaN/GaN quantum wells are presented for various growth temperatures of the p-GaN layer. The values of the diffusion coefficient estimated for true growth temperatures of 860, 910, and 980°C were 7.5·10–17, 2.8·10–16, and 1.2·10–15 cm2/s, respectively. The temperature values given in the work were measured on the surface of the growing layer in situ using a pyrometer. The calculated activation energy for the temperature dependence of the diffusion coefficient was 2.8 eV