Cross-platform Simulation of Bipolar Junction Transistor Electrical Principle

This paper designs a set of simulation method about bipolar junction transistor (short for ‘BJT’) electrical principle, which can be used as the foundation of cross-platform simulation of semiconductor electronic technology. Firstly, a mathematical model is established to simulate the amplification effect of bipolar junction transistor current control, the influence of Base current and Collector-Emitter Voltage on the working area of bipolar junction transistor. Secondly, interactive multimedia such as graphics, images and animation are used for simulation presentation through cross-platform software design method which is the mainstream internet web page interaction technology. Finally, a logic structure of the whole simulation software is designed, which presents data transmission, control workflow, relationship between each class and each layer in the simulation software.

Efficient Ohmic contacts and built-in atomic sublayer protection in MoSi2N4 and WSi2N4 monolayers

Metal contacts to two-dimensional (2D) semiconductors are often plagued by the strong Fermi level pinning (FLP) effect which reduces the tunability of the Schottky barrier height (SBH) and degrades the performance of 2D semiconductor devices. Here, we show that MoSi2N4 and WSi2N4 monolayers—an emerging 2D semiconductor family with exceptional physical properties—exhibit strongly suppressed FLP and wide-range tunable SBH. An exceptionally large SBH slope parameter of S ≈ 0.7 is obtained which outperforms the vast majority of other 2D semiconductors. Such intriguing behavior arises from the septuple-layered morphology of MoSi2N4 and WSi2N4 monolayers in which the semiconducting electronic states are protected by the outlying Si–N sublayer. We identify Ti, Sc, and Ni as highly efficient Ohmic contacts to MoSi2N4 and WSi2N4 with zero interface tunneling barrier. Our findings reveal the potential of MoSi2N4 and WSi2N4 as a practical platform for designing high-performance and energy-efficient 2D semiconductor electronic devices.

Progress in Photocatalysis of g-C3N4 and its Modified Compounds

Recently, graphitic carbon nitride (g-C3N4), a polymeric semiconductorhas been widely used as a low-cost, stable, and metal-free visible-light-active photocatalyst in the sustainable utilization of solar energy, such as water splitting, organic photosynthesis, and environmental remediation, which has attracted world wide attention from energy and environmental relative fields. Base on analysis of structure and theoretical calculation, the reasons that g-C3N4 can be used as a non-metallic catalyst were discussed in this paper. Some group's research jobs that metal-supported g-C3N4, metal-supported g-C3N4/organnic semiconductor compound and heterogeneous junction adjust the semiconductor electronic band structure have been summarized. And the mechanism, effect factors, and research developments on the reaction of organic degradation by photocatalytic and splitting water for hydrogen revolution catalyzed by above-mentioned modified g-C3N4 were emphatically analyzed. Finally, the prospects for the development of highly efficient g-C3N4 based photocatalysts are also discussed.

Deep Trapping Centers Relaxation in Transistors and Integrated Circuits

For ensuring the efficiency of the semiconductor electronic component base for apparatus, responsible for application, an optimal combination of statistical (group) and physical-technological (individual) reliability assessments is required. In the paper a thermodynamic approach, based on the deep-level transient spectroscopy in semiconductors promising means of individual rejection of potentially unreliable electronic component base has been proposed. For transistors and integrated circuits, the dependences of the amplitude of capacitance transient, caused by the bulk and surface defects of various nature on the repetition rate of electric filling pulses of deep levels, have been obtained. For multi-pin CMOS IC, the two-pole connection schemes to the spectrometer have been proposed. The obtained dependences show individual differences of studied specimens of various manufacturers as well as individual specimens from the same production batch. The performed studies have shown the promises of using the methods of the relaxation spectroscopy of deep level as the means of additional quality control of semiconductor devices and CMOS microcircuits both in the production process and in rejection of the items with potential defects, not specified by the project of engineering defect formation.

Unsharpness of Thermograms in Thermography Diagnostics of Electronic Elements

Work temperature is a factor, which has a strong influence on the work of a semiconductor electronic element. Operation of an electronic element in an excessive temperature causes the element not to work correctly. For this reason, monitoring the temperature of the element is necessary. One of the methods, which allows the monitoring of electronic element temperature is thermography. This non-contact method can also be used during the operation of the electronic element. The reading of a thermal camera depends on several factors. One of these factors is the sharpness of the registered thermograms. For this reason, research was carried out to develop a simple tool that allows a clear classification of thermograms of electronic elements into sharp and unsharp thermograms. In the research carried-out, the sharpness of the registered thermograms of electronic elements was determined by different sharpness measures. In the research, it was shown that in the case of thermograms classified as sharp, a smaller error of temperature measurement was obtained with the use of a thermal imaging camera.