Photoluminescence Imaging at Uniform Excess Carrier Density Using Adaptive Nonuniform Excitation

2018 ◽  
Vol 8 (6) ◽  
pp. 1787-1792
Author(s):  
Yan Zhu ◽  
Friedemann D. Heinz ◽  
Mattias Juhl ◽  
Martin C. Schubert ◽  
Thorsten Trupke ◽  
...  
1995 ◽  
Vol 379 ◽  
Author(s):  
H.T. Lin ◽  
D.H. Rich ◽  
A. Larsson

ABSTRACTThe effects of strain-induced defects on excess carrier lifetime and transport in a nipi-doped In0.2Ga0.8As/GaAs multiple quantum well (MQW) structure were examined with a new method called electron beam-induced absorption modulation (EBIA) in which the kinetics of carrier transport and recombination are examined with a high-spatial, -spectral and -temporal resolution. The excess carrier lifetime and ambipolar diffusion were found to be reduced by factors of ∼1013 and ∼103 compared to theoretical values, respectively, and this is attributed to the presence of strain-induced defects. The MQW excitonic absorption coefficient sensitively depends on the carrier density in the QWs, as a result of screening of the electron-hole (e-h) Coulombic interaction. Likewise, ambipolar diffusion is found to depend on the excess carrier density in a nonlinear fashion, as a result of the e-h plasma-induced changes in the local depletion widths in the vicinity of structural defects.


2018 ◽  
Vol 31 (2) ◽  
pp. 313-328 ◽  
Author(s):  
Dragana Markushev ◽  
Dragan Markushev ◽  
Slobodanka Galovic ◽  
Sanja Aleksic ◽  
Dragan Pantic ◽  
...  

The temperature distributions in the n-type silicon circular plate, excited by a frequency-modulated light source from one side, are investigated theoretically in the frequency domain. The influence of the photogenerated excess carrier density on the temperature distributions is considered with respect to the sample thickness, surface quality and carrier lifetime. The presence of the thermalization and non-radiative recombination processes are taken into account. The existence of the fast and slow heat sources in the sample is recognized. It is shown that the temperature distribution on sample surfaces is a sensitive function of an excess carrier density under a bulk and surface recombination. The most favorable values of surface velocities ratio and bulk lifetime are established, assigned for a simpler and more effective analysis of the carrier influence in semiconductors. The photothermal and photoacoustic transmission detection configuration is proposed as a most suitable experimental scheme for the investigation of the excess carrier influence on the silicon surface temperatures.


2015 ◽  
Vol 5 (3) ◽  
pp. 932-937 ◽  
Author(s):  
Jan Deckers ◽  
Maarten Debucquoy ◽  
Ivan Gordon ◽  
Robert Mertens ◽  
Jozef Poortmans

2012 ◽  
Vol 717-720 ◽  
pp. 309-312 ◽  
Author(s):  
Kęstutis Jarašiūnas ◽  
Patrik Ščajev ◽  
Tadas Malinauskas ◽  
Masashi Kato ◽  
Evgenii Ivakin ◽  
...  

Optical monitoring of diffusivity in wide bandgap semiconductors was performed by using a picosecond light-induced transient grating technique. The bandgap renormalization and carrier-carrier scattering manifested itself at room temperature as two-fold decrease of the ambipolar diffusion coefficient Da in cubic SiC and 5-fold decrease of Da in diamond at excess carrier density N > 1017cm-3, while for GaN the impact was observed only at T 19cm-3, the plasma degeneracy led to enhanced Davalues in SiC and GaN and compensated the diffusivity decrease in diamond.


1961 ◽  
Vol 39 (5) ◽  
pp. 754-767 ◽  
Author(s):  
C. H. Champness

The field-free diffusion of minority carriers injected at a point in silicon has been studied and the time from injection to the maximum of the collector signal due to the arriving carriers measured for various emitter–collector distances. Firstly, it was found that for 2-ohm-cm, 6-microsecond, n-type material the time to maximum was proportional approximately to the emitter–collector spacing raised to the power 1.2 for flat surfaces and to the power 1.6 for 3- and 6-degree wedge samples. The power 1.6 was also found for a 17-degree wedge of 120-ohm-cm, 100-microsecond, p-type silicon. Secondly, decay times following the maxima appeared to increase with emitter–collector spacing. No adequate two-surface theory is available but comparison with a one-surface theory revealed serious disagreements. It would appear that the results may be explained qualitatively by assuming that the effective lifetime is dependent on the excess carrier density and decreases as the emitter point is approached.


2011 ◽  
Vol 110 (6) ◽  
pp. 063708 ◽  
Author(s):  
F. E. Rougieux ◽  
B. Lim ◽  
J. Schmidt ◽  
M. Forster ◽  
D. Macdonald ◽  
...  

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