Influence of surface recombination and the life time of minority carriers on the characteristics of MESFET (OPFET) GaN

Optik ◽  
2021 ◽  
pp. 166479
Author(s):  
Issam Hamma ◽  
Toufik Ziar ◽  
Hichem Farh ◽  
Yasmina Saidi ◽  
Cherifa Azizi
Keyword(s):  
Surface Recombination ◽  
Life Time ◽  
Minority Carriers

Improvement of life time of minority carriers in GaAs epi-layer grown on Ge substrate

1998 ◽  
Vol 50 (1-4) ◽  
pp. 273-280 ◽  
Author(s):  
Ken Takahashi ◽  
Shigeki Yamada ◽  
Ryuichi Nakazono ◽  
Yasushi Minagawa ◽  
Takayuki Matsuda ◽  
...  
Keyword(s):  
Life Time ◽  
Minority Carriers

scholarly journals CONSIDERATION OF SURFACE RECOMBINATION WHEN MEASURING THE RECOMBINATION LIFETIME FROM THE PHOTOCONDUCTIVITY DECAY IN LARGE-THICKNESS SAMPLES

2020 ◽  
Author(s):  
Svetlana Kobeleva ◽  
Ivan Schemerov ◽  
Artem Sharapov ◽  
Sergey Yurchuk
Keyword(s):  
Diffusion Length ◽  
Decay Curve ◽  
Surface Recombination ◽  
Life Time ◽  
Free Carrier ◽  
Silicon Sample ◽  
Recombination Lifetime ◽  
Carrier Recombination ◽  
Photoconductivity Decay ◽  
Effective Life

Surface recombination strongly influence on the photoconductivity decay curve. In this work it was shown that usually defined using this curve the effective life time don’t achieve maxima value if silicon sample thickness exceeds six diffusion length. In this case well known formulas for calculation of free carrier recombination lifetime need to be adjusted.

scholarly journals Effect of Surface Recombination on Diffusion Length and Active Cavity Life time

2020 ◽  
pp. 3215-3220
Author(s):  
Ali H. Khidhir
Keyword(s):  
Diffusion Length ◽  
Optical Cavity ◽  
Surface Recombination ◽  
Optimization Procedure ◽  
Life Time ◽  
Optical Path Length ◽  
Specific Absorption ◽  
Switching Power ◽  
Fabry Perot ◽  
Simulation Systems

This work presents an analytical study for simulating a Fabry-Perot Bi-stable etalon (F-P cavity) filled with a dispersive optimized nonlinear optical material (Kerr type) such as semiconductors Indium Antimonite (InSb). Depending on the obtained results and because of a trade-off between the optical path length of the sample and active cavity lifetime, an optimization procedure was applied on the InSb etalon/CO laser parameters; critical switching irradiance (Ic) was applied via simulation systems  of optimization procedures of optical cavity (Matlap program was used to study the optical Bi-stability of a nonlinear Fabry-Perot cavity). In order to achieve minimum switching power and faster switching time, the optimization surface recombination on the diffusion length and effective cavity lifetime was studied. In addition, for a specific absorption value 400 cm-1, the lifetime coefficient  values were 0.33 , 0.091 , 0.0172 ns for sample thickness (D) = 500 , 60 , 20 mm, respectively. Also, for a bulk recombination time (Tl) of 200 ns, specific absorption (α) of 50 cm1, and D of 20 mm, the surface recombination speed value was  2.845 x 105 cm/sec, whereas the active lifetime, which is defined as the thickness over the surface recombination speed (sυ) (D/2sυ), was equal to 3.5ns.

scholarly journals Deep Centers and Persistent Photoconductivity Studies in Variously Grown GaN Films

2000 ◽  
Vol 5 (S1) ◽  
pp. 929-935 ◽  
Author(s):  
Alexander Y. Polyakov ◽  
Nikolai B. Smirnov ◽  
Anatoliy V. Govorkov ◽  
Alexander S. Usikov ◽  
Natalie M. Shmidt ◽  
...  
Keyword(s):  
Surface Recombination ◽  
Deep Levels ◽  
Lower Half ◽  
Total Density ◽  
Persistent Photoconductivity ◽  
High Concentration ◽  
Electron Traps ◽  
Deep Centers ◽  
Minority Carriers

Deep levels studies on a set of n-GaN films grown by MOCVD and HVPE reveal the presence of electron traps with levels near Ec−0.25 eV, Ec−0.55 eV, Ec−0.8 eV, Ec−1 eV, hole traps with levels near Ev+0.9 eV and a band of relatively shallow states in the lower half of the bandgap. The total density of these latter states was estimated to be some 1016 cm−3 and they were tentatively associated with dislocations in GaN based on their high concentration and band-like character. None of the electron or hole traps could be unambiguously related with strong changes of diffusion lengths of minority carriers in various samples. It is proposed that such changes occur due to different surface recombination velocities. An important role of Ec−0.55 eV traps in persistent photoconductivity phenomena in n-GaN has been demonstrated.

Deep Centers and Persistent Photoconductivity Studies in Variously Grown GaN Films

1999 ◽  
Vol 595 ◽  
Author(s):  
Alexander Y. Polyakov ◽  
Nikolai B. Smirnov ◽  
Anatoliy V. Govorkov ◽  
Alexander S. Usikov ◽  
Natalie M. Shmidt ◽  
...  
Keyword(s):  
Surface Recombination ◽  
Deep Levels ◽  
Lower Half ◽  
Total Density ◽  
Persistent Photoconductivity ◽  
High Concentration ◽  
Electron Traps ◽  
Deep Centers ◽  
Minority Carriers

AbstractDeep levels studies on a set of n-GaN films grown by MOCVD and HVPE reveal the presence of electron traps with levels near Ec-0.25 eV, Ec-0.55 eV, Ec-0.8 eV, Ec-1 eV, hole traps with levels near Ev+0.9 eV and a band of relatively shallow states in the lower half of the bandgap. The total density of these latter states was estimated to be some 1016 cm−3 and they were tentatively associated with dislocations in GaN based on their high concentration and band-like character. None of the electron or hole traps could be unambiguously related with strong changes of diffusion lengths of minority carriers in various samples. It is proposed that such changes occur due to different surface recombination velocities. An important role of Ec-0.55 eV traps in persistent photoconductivity phenomena in n-GaN has been demonstrated.

Surface Recombination Measurements in HgCdTe by Optical Modulation Frequency Response

1986 ◽  
Vol 90 ◽  
Author(s):  
J. A. Mroczkowski ◽  
E. Lesondak ◽  
D. Resler
Keyword(s):  
Frequency Response ◽  
Electron Concentration ◽  
Modulation Frequency ◽  
Surface Recombination ◽  
Life Time ◽  
Excess Electron ◽  
Optical Modulation ◽  
Interface Recombination ◽  
Interface Recombination Velocity ◽  
Recombination Velocity

ABSTRACTThe frequency response in the modulation of the excess electron concentration, produced by a modulated photogenerating pump beam, is used to determine bulk life-time and the surface or interface recombination velocity. The depth-wise integrated excess electron concentration is contactlessly monitored by the proportional absorption/ transmission modulation of a second probe beam. Using this approach over the 20 kHz to 3 MHz frequency range recombination velocities up to 104 cm/sec have been measured in n-type epitaxial HgCdTe films.

SEM and Auger microanalysis studies of Cu-Be dynode surfaces at each activation condition

1978 ◽  
Vol 36 (1) ◽  
pp. 524-525
Author(s):  
T. Koshikawa ◽  
Y. Fujii ◽  
E. Sugata ◽  
F. Kanematsu
Keyword(s):  
Electron Emission ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
Life Time ◽  
Activation Process ◽  
Beam Diameter ◽  
Activation Temperature ◽  
Electron Multiplier ◽  
Activation Condition ◽  
Activation Conditions

The Cu-Be alloys are widely used as the electron multiplier dynodes after the adequate activation process. But the structures and compositions of the elements on the activated surfaces were not studied clearly. The Cu-Be alloys are heated in the oxygen atmosphere in the usual activation techniques. The activation conditions, e.g. temperature and O2 pressure, affect strongly the secondary electron yield and life time of dynodes.In the present paper, the activated Cu-Be dynode surfaces at each condition are investigated with Scanning Auger Microanalyzer (SAM) (primary beam diameter: 3μmϕ) and SEM. The commercial Cu-Be(2%) alloys were polished with Cr2O3 powder, rinsed in the distilled water and set in the vacuum furnance.Two typical activation condition, i.e. activation temperature 730°C and 810°C in 5x10-3 Torr O2 pressure were chosen since the formation mechanism of the BeO film on the Cu-Be alloys was guessed to be very different at each temperature from the results of the secondary electron emission measurements.

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