Optimization techniques for p-GTO thyristor design

A new type of semiconductor power device was devised in the early ’90s as an alternative to the classic Gate Turn-Off (GTO) thyristor. Because the low-doped n-base was replaced by a low-doped p-base, it was called the p-GTO. Its main advantage is a higher possible control voltage when the device is switched off, leading to the possibility of a higher blocking anode current (IATO) and a lower turn-off time. The studies and techniques employed with the help of SILVACO-TCAD simulation software Athena and Atlas show that the p-GTO has higher breakdown voltages compared with its classic counterpart and similar on-state voltage (VT) and switching characteristics when replacing the GTO in the same circuit. Specific circuit improvements, like an affordable higher turn-off gate voltage, will drive the p-GTO into even faster switching operation.

Design of a Step-Up DC–DC Converter for Standalone Photovoltaic Systems with Battery Energy Storages

This paper proposes a step-up DC–DC converter for a power electronic circuit for standalone photovoltaic systems with battery energy storages. The proposed DC–DC converter effectively converts low DC battery voltage into high DC-link voltage. It operates with soft-switching characteristics, which can reduce switching power losses. The proposed converter operates without output voltage feedback, which simplifies its control design. The operation principle of the proposed converter was described, along with the overall system configuration. The experimental results were discussed for the 500-W prototype system using a 12-V lead-acid battery.

Analysis of Electrical Characteristics in 4H-SiC Trench-Gate MOSFETs with Grounded Bottom Protection p-Well Using Analytical Modeling

A new analytical model to analyze and optimize the electrical characteristics of 4H-SiC trench-gate metal-oxide-semiconductor field-effect transistors (TMOSFETs) with a grounded bottom protection p-well (BPW) was proposed. The optimal BPW doping concentration (NBPW) was extracted by analytical modeling and a numerical technology computer-aided design (TCAD) simulation, in order to analyze the breakdown mechanisms for SiC TMOSFETs using BPW, while considering the electric field distribution at the edge of the trench gate. Our results showed that the optimal NBPW obtained by analytical modeling was almost identical to the simulation results. In addition, the reverse transfer capacitance (Cgd) values obtained from the analytical model correspond with the results of the TCAD simulation by approximately 86%; therefore, this model can predict the switching characteristics of the effect BPW regions.

Study and Optimization of Field Limiting Rings for 10kV SiC Insulated Gate Bipolar Transistor

A 10kV-level silicon carbide (SiC) insulated gate bipolar transistor (IGBT) with field limiting rings (FLRs) is designed and simulated with Sentaurus TCAD, the detailed optimization method and comparisons are presented in this paper. Linearly varying spacing between rings is introduced to SiC IGBT and adjustment is performed on width of rings, the final structure achieves a breakdown voltage over 12kV with a termination length of 164.5 µm , which is 69.93% lower than that of conventional structure with a fixed ring spacing. Moreover, the final design can decrease the sensitivity to the interface charges, the tolerance to positive surface charges exceeds 8 × 10 11 cm − 2 , which is 3.5 times that of the conventional structure. Besides, double pulse measurements prove no degradation of conduction and switching characteristics.

Light-activated Multilevel Resistive Switching Storage in Pt/Cs2AgBiBr6/ITO/Glass Devices

High-density Cs2AgBiBr6 films with uniform grains were prepared by a simple one-step and low-temperature sol–gel method on indium tin oxide (ITO) substrates. An explicit tristate bipolar resistance switching behavior was observed in the Pt/Cs2 AgBiBr6/ITO/glass devices under irradiation of 10 mW/cm2 (445 nm). This behavior was stable over 1200 s. The maximum ratio of the high and low resistance states was about 500. Based on the analysis of electric properties, valence variation and absorption spectra, the resistive switching characteristics were attributed to the trap-controlled space charge-limited current mechanism due to the bromine vacancies in the Cs2AgBiBr6 layer. On the other hand, it is suggested that the ordering of the Schottky-like barrier located at Pt/Cs2AgBiBr6 affects the three-state resistance switching behavior under light irradiation. The ability to adjust the photoelectrical properties of Cs2AgBiBr6-based resistive switching memory devices is a promising strategy to develop high-density memory. Graphical Abstract