Өзбекстан республикасы жоқары ҳӘм орта арнаўлы билим министрлиги

MINISTRY OF HIGHER AND SECONDARY SPECIAL EDUCATION OF THE REPUBLIC OF UZBEKISTAN
KARAKALPAK STATE UNIVERSITY NAMED AFTER BERDAK

Faculty: Master's Department
Chair: Physics
Academic year: 2021-2022
Master’s student: Kulbayev G.G
Research advisor: Muratov A.S
Specialty: Theoretical physics

Theme: The formation of negative differential resistance in semiconductor structures
ANNOTATION
Relevance and necessity of the dissertation topic. Today, the world pays great attention to the study of the processes of controlling the parameters of the photoelectric characteristics of diodes with negative resistance, the effect of electric field and light radiation, as well as to determine their applicability to bipolar signal processing. Targeted research in this area, in particular: to determine the interdependence of the dynamic characteristics of long diodes on the lifetime of non-core charge carriers; one of the important tasks is to determine the active and reactive properties of the long diode in both positive and negative differential resistance areas.
The American scientist N. Kholonyak showed that in a double-injection of a semiconductor-insulator structure, a negative differential resistance is observed, which reduces the threshold voltage when the structure is illuminated. A similar effect was observed by Robert Keyes in a case compensated by the introduction of zinc in germanium.
Russian scientists V. I. Stafeev and I. M. Vikulin obtained the internal amplification effects of photocurrent on injection diodes and gave examples of the formation of S-shaped current characteristics. D.A.Usanov and A.A.Semenov also found that diode structures with capacitive negative differential resistance connected in parallel behave like generators of electric oscillations, the frequency of which increases with increasing slip current. It was also found that a semiconductor-dielectric heterocontact forms a potential trap for electrons at the boundary with the dielectric, the concentration of which is higher than the concentration in the semiconductor, which provides a high density of emission currents. The explanation of the processes of formation of negative differential resistance is carried out in a quasi-equilibrium diffusion approximation.
The practical application of semiconductor devices depends on the effects that can be observed on them. With the development of microelectronics, the double injection process became a separate theory. The size of a semiconductor is called the double injection of electrons and holes into both sides at the same time. Injected chargers vary in mobility and lifetime. In some cases, their lifetimes change as a result of the effects on the diode, resulting in a variety of events.