Analysis of Flexural Vibrations of a Piezoelectric Semiconductor Nanoplate Driven by a Time-Harmonic Force

The performance of devices fabricated from piezoelectric semiconductors, such as sensors and actuators in microelectromechanical systems, is superior; furthermore, plate structures are the core components of these smart devices. It is thus important to analyze the electromechanical coupling properties of piezoelectric semiconductor nanoplates. We established a nanoplate model for the piezoelectric semiconductor plate structure by extending the first-order shear deformation theory. The flexural vibrations of nanoplates subjected to a transversely time-harmonic force were investigated. The vibrational modes and natural frequencies were obtained by using the matrix eigenvalue solver in COMSOL Multiphysics 5.3a, and the convergence analysis was carried out to guarantee accurate results. In numerical cases, the tuning effect of the initial electron concentration on mechanics and electric properties is deeply discussed. The numerical results show that the initial electron concentration greatly affects the natural frequency and electromechanical fields of piezoelectric semiconductors, and a high initial electron concentration can reduce the electromechanical fields and the stiffness of piezoelectric semiconductors due to the electron screening effect. We analyzed the flexural vibration of typical piezoelectric semiconductor plate structures, which provide theoretical guidance for the development of new piezotronic devices.

DESIGN OF HUMAT ACID SOLID SOLUTION REACTOR THROUGH PHOTOTRANSFORMATION OF COPPER OXIDE (CuO) SEMICONDUCTOR PLATE

This research was conducted to make the reactor degrade a solution of humic acid using a copper oxide (CuO) catalyst. The designed reactor consists of 2 types of design, the first reactor consists of 8 copper oxide semiconductors (CuO) as catalyst with a sample volume of 1600 ml and a second reactor consisting of 1 copper oxide (CuO) with a sample volume of 25 ml. The light source used is direct sunlight and light in the room. The catalytic process is carried out through photodegradation of a solution of humic acid using the reactor. Variations in irradiation time are carried out for 2, 4, 6 and 8 hours. Absorbance of humic acid before and after irradiation was measured using spronics at 325 nm. The results showed that direct sunlight irradiation gave better results than light rays in the room. The optimum exposure to sunlight is 4 hours with degradation of 32.80% using a second type of reactor.

Investigation of porosity and fractal properties of the sintered metal and semiconductor layers in the MDS capacitor structure

MDS capacitor (metal - dielectric - semiconductor) is a structure in which metal plate is represented by compact bulk-porous pellets of niobium sintered powder, and semiconductor plate - by pyrolytic layer of MnO2. In the present paper we report the results of investigation of microporosity of sintered Nb and pyrolytic MnO2 and also the fractal properties of semiconductor layer.