Применение подсветки контактов для измерений проводимости высокоомных полупроводников
The influence of light illumination of ohmic contacts to high-ohmic gallium arsenide and cadmium telluride samples is investigated. It is revealed, that near-contact –area illumination influences not only upon transition resistance, but also upon volume conductivity of the samples due to increasing of free carrier concentration. The new method of separate determination of ohmic contact transition resistance and sample volume resistance is suggested, suitable for high-ohmic semiconductors. The qualitative model, explaining sample volume conductivity increasing due to near-contact-area illumination, is proposed.
The influence of local illumination providing high level of free charge carrier injection upon semiinsulating cadmium telluride sample conductivity and properties of ohmic contacts to the sample is investigated. It is revealed, that independently upon illumination region the value of ohmic contact transition resistance decreases and main charge carrier concentration increases proportionally illumination intensity. Light probe scanning is shown to be suitable for investigation of intrinsic semiinsulating semiconductor crystal inhomogenuities
The present work describes the step-by-step development of an automated control and measuring system that monitors the electrical and thermal parameters of pulsed secondary power supplies (SPS) for laptops. The main guidance documents are considered, according to which the design of impulse SPS laptops is carried out. It is revealed that the existing methods for controlling the parameters of pulsed SPS laptops take into account only electrical, however, the thermal parameters make a significant contribution to the result of numerical values of electrical parameters. In this regard, an improved method for controlling both electrical and thermal parameters of pulsed secondary power supplies is proposed. The structure of the automated control and measuring system as a whole, as well as the structure of the multifunctional hardware platform with all its components are developed.
The photoemission of free charge carriers into high-ohmic semiconductor created by light illumination of near-contact-area of ohmic contacts to cadmium telluride sample was investigated. It was revealed, that near-contact-area light illumination influences both on contact transition resistance and on volume conductivity of the crystal due to increasing of main charge carrier concentration. The method of separate determination of contact transition and sample volume resistances, suitable for high-ohmic semiconductors, was suggested.
This volume presents new results in the study and optimization of information transmission models in telecommunication networks using different approaches, mainly based on theiries of queueing systems and queueing networks .
The paper provides a number of proposed draft operational guidelines for technology measurement and includes a number of tentative technology definitions to be used for statistical purposes, principles for identification and classification of potentially growing technology areas, suggestions on the survey strategies and indicators. These are the key components of an internationally harmonized framework for collecting and interpreting technology data that would need to be further developed through a broader consultation process. A summary of definitions of technology already available in OECD manuals and the stocktaking results are provided in the Annex section.