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.

Ultrafast Relaxation Character of Nonequilibrium Carriers in GaAs Excited by Femtosecond Laser

2006 ◽  
Vol 532-533 ◽  
pp. 572-575
Author(s):  
Ming Zhou ◽  
Dong Qing Yuan ◽  
Li Peng Liu ◽  
Hui Xia Liu ◽  
Nai Fei Ren
Keyword(s):  
Femtosecond Laser ◽  
Relaxation Curve ◽  
Refraction Index ◽  
Free Carrier ◽  
Index Of Refraction ◽  
Lattice Temperature ◽  
Pump Probe ◽  
Recombination Lifetime ◽  
Carrier Effect ◽  
Carrier Recombination

Experiment setup of femtosecond laser pump probe was established, the time resolution of time-delay setting reached 67fs. By use of femtosecond laser with width of 30fs and wavelength is 796nm the dependence of transient change of reflectivity on delayed time in GaAs was measured by pump-probe method. By calculating the change of complex index of refraction (%n), free-carrier effect, lattice-temperature and carrier recombination contributions to relaxation curve was analyzed. When the carrier density N is 1.44×1018/cm3, free-carrier contribution to refraction index %nFC is -7.33×10-4, lattice-temperature %nLT is 0.85×10-4. Based on recombination rate equation, recombination lifetime of 980ps was deduced.

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.

Influence of Epilayer Thickness and Structural Defects on the Minority Carrier Lifetime in 4H-SiC

2013 ◽  
Vol 740-742 ◽  
pp. 633-636 ◽  
Author(s):  
Birgit Kallinger ◽  
Patrick Berwian ◽  
Jochen Friedrich ◽  
Mathias Rommel ◽  
Maral Azizi ◽  
...  
Keyword(s):  
Carrier Lifetime ◽  
Minority Carrier ◽  
Deep Level ◽  
Surface Recombination ◽  
Minority Carrier Lifetime ◽  
Structural Defects ◽  
Effective Lifetime ◽  
Recombination Lifetime ◽  
Photoconductivity Decay ◽  
Transient Spectroscopy

4H-SiC homoepitaxial layers with different thicknesses from 12.5 µm up to 50 µm were investigated by microwave-detected photoconductivity decay (µ-PCD), deep level transient spectroscopy (DLTS) and defect selective etching (DSE) to shed light on the influence of the epilayer thickness and structural defects on the effective minority carrier lifetime. It is shown that the effective lifetime, resulting directly from the µ-PCD measurement, is significantly influenced by the surface recombination lifetime. Therefore, an adequate correction of the measured data is necessary to determine the bulk lifetime. The bulk lifetime of these epilayers is in the order of several microseconds. Furthermore, areas with high dislocation density are correlated to areas with locally reduced effective lifetime.

Ultraviolet (UV) Irradiation Effect on Minority-Carrier Recombination Lifetime in Silicon Wafers with Oxide and Nitride Films

1993 ◽  
Vol 318 ◽  
Author(s):  
L. Zhong ◽  
F. Shimura
Keyword(s):  
Uv Irradiation ◽  
Minority Carrier ◽  
Correlation Energy ◽  
Surface Recombination ◽  
Chemical Vapor ◽  
Charge Trapping ◽  
Dielectric Films ◽  
Irradiation Effect ◽  
Recombination Lifetime ◽  
Carrier Recombination

ABSTRACTA new method based upon photoconductance measurement of the minority-carrier recombination lifetime is developed to investigate defects both in dielectric films and on the interface. In this method, surface recombination process in silicon substrate is used as a probe to detect the interface traps generated by ultraviolet (UV) irradiation as well as the defects in a film whose electronic state can be excited by UV irradiation. A variety of films, including native, chemical vapor deposited (CVD) and thermal oxide as well as CVD nitride, have been studied. In CVD nitride, for example, evidence is provided that K-centers, the main charge trapping defects, have a negative correlation energy (negative-U).

Noncontact Characterization for Ultraviolet Light Irradiation Effect on Si-SiO2 Interface

1992 ◽  
Vol 262 ◽  
Author(s):  
K. Katayama ◽  
F. Shimura
Keyword(s):  
Minority Carrier ◽  
Surface Recombination ◽  
Native Oxide ◽  
Dominant Factor ◽  
Irradiation Effect ◽  
Recombination Lifetime ◽  
Carrier Recombination ◽  
Thermal Oxide ◽  
Ultraviolet Light Irradiation ◽  
Recombination Centers

ABSTRACTThe effect of ultraviolet (UV) irradiation on the minority-carrier surface recombination lifetime (τs) in silicon wafers with native or thermal oxide was studied with a noncontact laser/microwave photoconductance (LM-PC) technique. The τs greatly increases in samples with native oxide after the irradiation. The dominant factor for the τs change can be negative charges created by photo-injected electrons in the surface area. On the other hand, the irradiation decreases τs in silicon with thermal oxide. The τs decrease is due to the generation of carrier recombination centers with an energy level around 0.2eV at the Si-SiO2 interface.

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