A General Analysis of Steady State Photocarrier Grating Technique for the Determination of Ambipolar Diffusion Length

1990 ◽  
Vol 192 ◽  
Author(s):  
Yuan-Min Li
Keyword(s):  
Steady State ◽  
Electric Field ◽  
Dielectric Relaxation ◽  
General Formula ◽  
Applied Electric Field ◽  
Diffusion Length ◽  
Ambipolar Diffusion ◽  
General Analysis

ABSTRACTA general photoconductivity formula is derived for the case of a semiconductor steady state photocarrier grating (SSPG)1. It is shown that, under the condition of weak applied electric field, the ambipolar diffusion length can be determined by the SSPG technique1without the lifetime-regime restriction2,3 if the lifetime of photocarriers is known. The general formula presented here is reduced to the simple lifetime-regime formula1–3 under the condition of fast dielectric relaxation.

A-Si:H Ambipolar Diffusion Length and Effective Lifetime Measured by Flying Spot Technique (FST)

1991 ◽  
Vol 219 ◽  
Author(s):  
M. Vieira ◽  
R. Martins ◽  
E. Fortunato ◽  
F. Soares ◽  
L. Guimaraes
Keyword(s):  
Laser Beam ◽  
Transient Analysis ◽  
Diffusion Length ◽  
Transport Equations ◽  
Ambipolar Diffusion ◽  
Schottky Barriers ◽  
Effective Lifetime ◽  
Asymmetrical Distribution ◽  
Flying Spot

ABSTRACTThe determination of the ambipolar diffusion length, L*, and the effective lifetime, τ*, in p/i and a-Si:H Schottky barriers (ITO/p/a-Si:H/Al-Si; Cr/a-Si:H/Cr/Ag) have been determined by Flying Spot Technique, FST. This technique consists in the transient analysis of the photocurrent/photopotential induced by a laser beam that moves perpendicularly to the structure with a constant motion ratio, at different velocities. Taking into account the competition between the diffusion/drift velocities of the excess carriers and the velocity of the flying spot, it is possible to solve the transport equations and to compute separately L* and τ*, from the asymmetrical distribution responses.

Ion trajectories in weak electrolytes

1980 ◽  
Vol 371 (1746) ◽  
pp. 413-427 ◽  
Keyword(s):  
Steady State ◽  
Electric Field ◽  
Applied Electric Field ◽  
Numerical Quadrature ◽  
Average Flow ◽  
Recombination Processes ◽  
Weak Electrolytes ◽  
The Mean ◽  
Charged Ions ◽  
Oppositely Charged

The equations of the mean relative trajectories of neighbouring oppositely charged ions in a weak electrolyte that has attained a steady state in a uniform applied electric field are determined analytically. Both the dissociation and recombination of ions are considered and the mean relative trajectories are defined in terms of the ensemble average flow patterns of the ions participating in these processes. For recombination of ions, the equation of the boundary of ionic attraction is also derived. The mean times involved in the dissociation and recombination processes are determined by using numerical quadrature. The results obtained are consistent with the Bjerrum (1926) theory of weak electrolytes.

scholarly journals Direct determination of the ambipolar diffusion length in GaAs/AlGaAs heterostructures by cathodoluminescence

1989 ◽  
Vol 55 (16) ◽  
pp. 1647-1649 ◽  
Author(s):  
H. A. Zarem ◽  
P. C. Sercel ◽  
J. A. Lebens ◽  
L. E. Eng ◽  
A. Yariv ◽  
...  
Keyword(s):  
Diffusion Length ◽  
Direct Determination ◽  
Ambipolar Diffusion
Sign in / Sign up

Export Citation Format

Share Document