Summary of the PhD thesis Theoretical and mathematical physics: Electronic transport in semiconductor nanostructure based on polar material AlGaN/GaN and Penta-Graphene nanoribbon

The purposes of research "Electronic transport in semiconductor nanostructure based on polar material AlGaN/GaN and Penta-Graphene nanoribbon" studying on electronic transport phenomena in semiconductor nano structures such as AlGaN/GaN and penta-graphene nanoribbon.
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Summary of the PhD thesis Theoretical and mathematical physics: Electronic transport in semiconductor nanostructure based on polar material AlGaN/GaN and Penta-Graphene nanoribbonMINISTRY OF EDUCATION VIETNAM ACADEMY OF AND TRAINING SCIENCE AND TECHNOLOGY GRADUATE UNIVERSITY SCIENCE AND TECHNOLOGY ……..….***………… PHAM THI BICH THAO ELECTRONIC TRANSPORT IN SEMICONDUCTOR NANOSTRUCTURE BASED ON POLAR MATERIAL AlGaN/GaN AND PENTA-GRAPHENE NANORIBBON Speciality: Theoretical and mathematical physics Code: 9 44 01 03 SUMMARY OF THE PHD THESIS Ha Noi – 2020 This thesis was completed at Graduate University of Science and Technology, Vietnam Academy of Science and TechnologySupervisors: Assoc. Prof. Dr. Nguyen Thanh Tien Prof. Dr. Doan Nhat QuangReferee 1: Assoc. Prof. Dr. Dinh Van TrungReferee 2: Prof. Dr. Dao Tien KhoaReferee 3: Dr. Pham Ngoc DongThis dissertation will be defended in front of the evaluating assembly atacademy level, place of defending: meeting room, Graduate Universityof Science and Technology, Vietnam Academy of Science andTechnology.This thesis can be studied at:- The Library of Graduate University of Science and Technology- The Vietnam National Library 1Introduction Nowadays, semiconductor technology is one of the most important fieldsin the development of science and technology. Semiconductor technology isa foundation of the information society that has been motivating human so-ciety forward by changing in production, living, communication and even inhuman. In semiconductor technology, semiconductor materials play a cru-cial role. The first transistor was invented in 1947 based on germanium (Ge)semiconductor with a band gap at room temperature of 0.66 eV. The firstintegrated circuit was born in 1958 and the bulk integrated circuit appearedin 1961 using germanium and silicon (Si) with a band gap of 1.12 eV. Since1965, silicon has become the main material for semiconductor integratedcircuits. Today, most semiconductor, integrated circuit or photovoltaic in-dustries are still based on silicon. Silicon and germanium are often referred as the first generation of semi-conductors. The second generation including gallium arsenide (GaAs, bandgap at room temperature is 1.42 eV) and indium phosphide (InP, band gapat room temperature 1.35 eV) was introduced in the 1970s. The second gen-eration is primarily used in high-speed devices, microwave devices and inte-grated circuits. Besides the larger band gap, the electron mobility of GaAsis more than six times larger than that of silicon. In addition, the saturationvelocity of GaAs is higher, i.e. two times larger than that of silicon. There-fore, devices based on GaAs are suitable for high-frequency operations. Inaddition, field-effect transistors based on GaAs also have advantages suchas low noise, high performance, ect. However, GaAs has lower thermal con-ductivity and disruptive potential than semiconductors like GaN and SiChave, resulting in capacity limitations. At the end of the twentieth century, the third generation of semicon-ductors (wide band gap) such as gallium nitride (GaN, band gap at roomtemperature: 3.45 eV) and silicon carbide (SiC, band gap in room temper-ature: 3.25 eV for 4H-SiC) show remarkable features, which have attracteda lot of attention. III nitride semiconductors including GaN, InN, AlN andtheir heterostructures can be widely applied to electronic and optoelectronic 2devices. The band gap of these structures range from the near infrared (0.7eV, InN) to the far ultraviolet (6.2 eV, AlN). In particular, compared withconventional III-V and II-IV semiconductors, spontaneous and piezoelectricpolarization in GaN and AlN with wuztzite structure is about ten timeslarger. Therefore, GaN, AlGaN / GaN, InGaN / GaN, ect can be applied tohigh electronic mobility transistor and heterojunction field effect transistor. Currently, semiconductor heterostructure is widely used in many fieldsdue to its great advantages. Specifically, in the telecommunication fieldwith semiconductor transistors, satellite television, warning systems, ect;Energy field with solar cell, light-emitting diode, information storage device,ect; Medical field with water filtration system, data processing system, ect.Many studies show that the electric and optical properties of heterostructuresemiconductor vary significantly compared to those of the bulk semiconduc-tor and by the external field. Moreover, the heterostructure semiconductoralso has superior intrinsic properties. One of the properties is that the po-larization depends on the direction of the material and the struct ...