Time Resolved Photoluminescence of Yb in InP

1987 ◽  
Vol 104 ◽  
Author(s):  
P. B. Klein
Keyword(s):  
Activation Energy ◽  
Valence Band ◽  
Low Temperatures ◽  
Weak Coupling ◽  
Thermal Activation ◽  
Thermal Activation Energy ◽  
Excited State Lifetime ◽  
Time Resolved ◽  
Exponential Component ◽  
Time Resolved Photoluminescence

ABSTRACTTime resolved photoluminescence (PL) measurements of the internal 4f-4f transitions of Yb3+ have been carried out in InP and GaP. In InP a nonexponential component is observed in the PL decay, and is interpreted in terms of carrier capture by nonequilibrium Yb3+. At low temperatures the exponential component is found to be much faster (≈12.5 μsec) than expected, and is tentatively associated with a weak coupling to resonant valence band states. As the temperature is increased, the PL intensity and the exponential component of the excited state lifetime are quenched with a thermal activation energy of ≈0.1 eV. This is interpreted as being due to the emission of a hole into the valence band by the neutral Yb acceptor.

SELF-TRAPPED EXCITONS IN ORTHORHOMBIC SnBr2

2001 ◽  
Vol 15 (28n30) ◽  
pp. 4009-4012 ◽  
Author(s):  
Y. YAMASAKI ◽  
N. OHNO
Keyword(s):  
Time Dependence ◽  
Low Temperatures ◽  
Luminescence Band ◽  
Radiative Decay ◽  
Time Resolved ◽  
Tunneling Recombination ◽  
Exciton Region ◽  
Time Resolved Photoluminescence ◽  
Stokes Shifts ◽  
2.5 Ev Luminescence

Luminescence properties of SnBr 2 have been studied to reveal the photo-excited exciton relaxation process. Two types of luminescence with large Stokes shifts are found at low temperatures; the 2.2-eV luminescence band produced under the photo-excitation in the first exciton region, and the 2.5-eV luminescence band stimulated by photons with energies above the bandgap. The time-resolved photoluminescence measurements have revealed that the 2.2-eV luminescence comprises fast (1.2 μs) and slow (6.4 μs) exponential decay components, whereas the 2.5-eV luminescence shows the time dependence of I(t)∞ t-0.9. These results suggest that the former band is attributed to the radiative decay of self-trapped excitons, and the latter band would originate from tunneling recombination of holes with the STEL as in the case of lead halides.

About the Electrical Activation of 1×1020 cm-3 Ion Implanted Al in 4H-SiC at Annealing Temperatures in the Range 1500 - 1950°C

2018 ◽  
Vol 924 ◽  
pp. 333-338 ◽  
Author(s):  
Roberta Nipoti ◽  
Alberto Carnera ◽  
Giovanni Alfieri ◽  
Lukas Kranz
Keyword(s):  
Activation Energy ◽  
Sheet Resistance ◽  
Annealing Time ◽  
Thermal Activation ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Thermal Activation Energy ◽  
Electrical Activation ◽  
Temperature Range ◽  
Annealing Temperatures

The electrical activation of 1×1020cm-3implanted Al in 4H-SiC has been studied in the temperature range 1500 - 1950 °C by the analysis of the sheet resistance of the Al implanted layers, as measured at room temperature. The minimum annealing time for reaching stationary electrical at fixed annealing temperature has been found. The samples with stationary electrical activation have been used to estimate the thermal activation energy for the electrical activation of the implanted Al.

Temperature/Doping-Dependency of the Electrical Properties of the Nickel Doped Copper Oxide Thin Films

2021 ◽  
Vol 16 (2) ◽  
pp. 163-169
Author(s):  
Alaa Y. Mahmoud ◽  
Wafa A. Alghameeti ◽  
Fatmah S. Bahabri
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Electrical Properties ◽  
Thermal Activation ◽  
Doping Concentration ◽  
Energy Gap ◽  
Cupric Oxide ◽  
Electrical Energy ◽  
Thermal Activation Energy ◽  
Ni Doping

The electrical properties of the Nickel doped cupric oxide Ni-CuO thin films with various doping concentrations of Ni (0, 20, 30, 70, and 80%) are investigated at two different annealing temperatures; 200 and 400 °C. The electrical properties of the films; namely thermal activation energy and electrical energy gap are calculated and compared. We find that for the non-annealed Ni-CuO films, both thermal activation energy and electrical energy gap are decreased by increasing the doping concentration, while for the annealed films, the increase in the Ni doping results in the increase in thermal activation energy and electrical energy gap for most of the Ni-CuO films. We also observe that for a particular concentration, the annealing at 200 °C produces lower thermal activation energy and electrical energy gap than the annealing at 400 °C. We obtained two values of the activation energy varying from -5.52 to -0.51 eV and from 0.49 to 3.36 eV, respectively, for the annealing at 200 and 400 °C. We also obtained two values of the electrical bandgap varying from -11.05 to -1.03 eV and from 0.97 to 6.71 eV, respectively, for the annealing at 200 and 400 °C. It is also noticeable that the increase in the doping concentration reduces the activation energy, and hence the electrical bandgap energies.

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