摘要:

A review is given of our present knowledge of metal-semiconductor contacts. Topics covered include the factors that determine the height of the Schottky barrier, its current/voltage characteristics, and its capacitance. A short discussion is also given of practical contacts and their application in semiconductor technology, and a comparison is made withp-njunctions.

DOI:10.1049/ip-i-1.1982.0001

出版商:IEE    

年代:1982

数据来源: IET

摘要:

Nonoptimised, conventional I2L can be fabricated in processes established for other types of logic, or those for analogue circuitry. These processes vary widely in the properties of epilayer, base doping and other process parameters. To explain I2L behaviour in such processes, the static and dynamic properties of I2L have been investigated over a wide range of epilayer doping concentration and thickness, active base resistivity etc. Some previous apparent contradictions about then-p-nbase current components are resolved. In addition it is demonstrated that the power-delay product at low injector current is not, in general, constant. Also, the dependence of intrinsic gate delay on epilayer doping is found to deviate from theoretical predictions. Possible reasons for the discrepancies are discussed.

DOI:10.1049/ip-i-1.1982.0002

出版商:IEE    

年代:1982

数据来源: IET

摘要:

The mechanism proposed by Matsunagaet al. to explain their observation of the injection of minority carriers into the substrate of a saturatedn-channel MOST does not explain similar experimental results obtained usingn-p-nbipolar transisitors. The alternative optical model proposed by Childset al. does, however, apply to both measurements if it is assumed that the probability of an electron emitting a photon when crossing a reverse-biased junction is proportional to (Mn− I)/Mn, whereMnis the electron multiplication factor in the junction.

DOI:10.1049/ip-i-1.1982.0003

出版商:IEE    

年代:1982

数据来源: IET

摘要:

Self-absorption of photons generated by prior luminescence processes affects both the steady-state and transient characteristics of LEDs. In this study we confine ourselves to one of the most important steadystate parameters-external quantum efficiency. It is shown that the photon self-absorption increases the injected carrier concentration, and consequently the emitted photon flux. This results in an increase in LED external quantum efficiency. A detailed analysis of this phenomenon is presented, and a simplified evaluation of its influence on the external quantum efficiency is given. Our calculation also takes into account multiple internal reflection of light generated inside the LED. The obtained results are applied to a diffused GaAs (Zn, Te) surface-emitting LED. It is estimated that the feedback carrier excitation (re-excitation) due to selfabsorption increases the LED external quantum efficiency by about 60% and multiple internal reflections by about 12%.

DOI:10.1049/ip-i-1.1982.0004

出版商:IEE    

年代:1982

数据来源: IET

摘要:

The presence of linear features commonly known as ‘dark-line defects’ is known to have a detrimental effect on the luminescence efficiency of some light-emitting diodes. The paper demonstrates the value of using SEM-CL and SEM-EBIC techniques, both for materials assessment before diode fabrication, and for evaluating the effect of various processing parameters. It is shown that commercial device-grade GaAs0.6P0.4material can contain substantial numbers of structural defects (in both the graded and constant-composition layers), many of which cause a marked reduction in the luminescence efficiency of the fabricated diodes. Device processing does not appear to cause further degradation in the operation of the diodes. The nature and origin of the defects are discussed.

DOI:10.1049/ip-i-1.1982.0005

出版商:IEE    

年代:1982

数据来源: IET