Effect of the reverse bias between channel and substrate on the effective mobility of electrons in a Ge i.g.f.e.t.

1977 ◽  
Vol 13 (20) ◽  
pp. 624
Author(s):  
Kvon Ze Don ◽  
G. Neizvestny ◽  
V.N. Ovsuyk
Keyword(s):  
Reverse Bias ◽  
Effective Mobility

On the Role of Charged Defect States and Deep Traps in the Photocarrier Drift and Diffusion in a-Si:H

2000 ◽  
Vol 609 ◽  
Author(s):  
Paul Stradins ◽  
Akihisa Matsuda
Keyword(s):  
Particle Number ◽  
Defect States ◽  
Total Electron ◽  
Minority Carrier Diffusion Length ◽  
Continuity Equations ◽  
Effective Mobility ◽  
Almost All ◽  
Charged Defects ◽  
And Diffusion

ABSTRACTThe drift and diffusion in the presence of charged defects and photocarriers trapped in the tail states is re-examined. In continuity equations, diffusive and drift currents are related to free particles while the Poisson equation includes all charges. In order to make use of ambipolar diffusion approximation, the mobilities and diffusion coefficients should be attributed to the total electron and hole populations making them strongly particle-number dependent. Due to the asymmetry of the conduction and valence band tails, almost all trapped electrons reside in negatively charged defects (D−). A simple model of photocarrier traffic via tail and defect states allows to establish the effective mobility values and coefficients in Einstein relations. In a photocarrier grating experiment, grating of D− is counterbalanced by the grating of trapped holes. Nevertheless, electrons remain majority carriers, allowing the measurement of minority carrier diffusion length, but analysis is needed to relate the latter with μτ product.

A New Prediction Model on the Luminance of OLEDs Subjected to Different Reverse Biases for Alleviating Degradation in AMOLED Displays

2014 ◽  
Author(s):  
Paul C.-P. Chao ◽  
Yen-Ping Hsu ◽  
Yung-Hua Kao ◽  
Kuei-Yu Lee
Keyword(s):  
Reverse Bias ◽  
High Efficiency ◽  
Life Time ◽  
Density Currents ◽  
High Brightness ◽  
Light Emitting ◽  
Wide Viewing Angle ◽  
Time Operation ◽  
Long Time ◽  
History Of

Organic light-emitting diodes (OLEDs) have drawn much attention in areas of displays and varied illumination devices due to multiple advantages, such as high brightness, high efficiency, wide viewing angle, and simple structure. However, the long-time degradation of OLED emission is a serious drawback. This degradation was investigated by past works, which pointed out that the degradation was induced by high-density currents through OLED component under the long-time operation [1][2]. Proposed by a past work [3], different reverse biases was imposed on OLED components in display frames to alleviate the long-time degradation on OLEDs. Most recently, along with the reverse bias, new pixel circuits [4][5] for AMOLED displays are designed to alleviate OLED degradation, thus successfully extending OLED life time. However, since emission luminances in different frame times during AMOLED displaying differs significantly for displaying varied images, the OLED degradation evolves in a highly unpredictable fashion. In this study, based on valid theories, the voltage across the OLED is first used as indicator for OLED degradation. Then the relation between the level of OLED degradation, in terms of OLED’s cross voltage, and the history of imposing reverse biases are precisely modeled. With the model, the degradation of the OLED under reverse bias to extend lifetime can be successfully predicted. Based on this model, engineers can then optimize the applied reverse bias on OLEDs to maximize the OLED lifetime for varied display requirement.

Evidence For Non-Correlation Between The 0.15 eV And 0.44 eV Cu-Related Acceptor Levels In GaAs

1996 ◽  
Vol 442 ◽  
Author(s):  
K. Leosson ◽  
H. P. Gislason
Keyword(s):  
Reverse Bias ◽  
Deep Level ◽  
Current Transient ◽  
Zero Bias ◽  
Lithium Diffusion ◽  
Transient Spectroscopy ◽  
Plasma Hydrogenation

AbstractWe present investigations on the two dominating acceptor levels observed in Cu-diffused GaAs which have frequently been attributed to the two ionization levels of a double CuGa acceptor. We employed plasma hydrogenation and lithium diffusion followed by reverse-bias and zero-bias annealing to passivate and subsequently reactivate the Cu-related acceptor levels. Deep-level current-transient spectroscopy measurements reveal that the two levels are independently reactivated, strongly indicating that they arise from different defects.

Scanned Electron Beam Annealing of Boron-Implanted Diodes

1980 ◽  
Vol 1 ◽  
Author(s):  
T. O. Yep ◽  
R. T. Fulks ◽  
R. A. Powell
Keyword(s):  
Electron Beam ◽  
Ion Implantation ◽  
Reverse Bias ◽  
Carrier Lifetime ◽  
Reverse Current ◽  
Electrical Activation ◽  
Electrical Characteristics ◽  
Low Resolution ◽  
Implantation Damage ◽  
Dopant Redistribution

ABSTRACTSuccessful annealing of p+ n arrays fabricated by ion-implantation of 11B (50 keV, 1 × 1014 cm-2) into Si (100 has been performed using a broadly rastered, low-resolution (0.25-inch diameter) electron beam. A complete 2" wafer could be uniformly annealed in ≃20 sec with high electrical activation (>75%) and small dopant redistribution (≃450 Å). Annealing resulted In p+n junctions characterized by low reverse current (≃4 nAcm-2 at 5V reverse bias) and higher carrier lifetime (80 μsec) over the entire 2" wafer. Based on the electrical characteristics of the diodes, we estimate that the electron beam anneal was able to remove ion implantation damage and leave an ordered substrate to a depth of 5.5 m below the layer junction.

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