Saidov Amin Safarbaevich

He was born on January 1, 1939, in the city of Mangit, Khorezm region, Uzbekistan.

Head of the Laboratory “Growth of semiconductor crystals” of the Physical-Technical Institute of the Uzbekistan Academy of Sciences. In 1959 the Laboratory was created by academician Saidov Mukhtar Safarboevich.

Area of ​​scientific interests:

The interaction of impurities in diamond-like semiconductors and the physical basis for the growth of silicon, gallium arsenide, aluminum-gallium arsenide, and also the high-resistivity, homogeneous and graded-gap solid solutions IV1-x-IVx, (IV2)1-x(A3B5)x, (IV2)1-x( A2B6)x, (IV2)1-x-y(A3B5)x (A2B6)y, as well as hetero-structures based on them.

Education:

1957-1962 – student at Samarkand State University (formerly State University of Uzbekistan)

1964-1966 intern – researcher at the A. F. Ioffe Physical-Technical Institute of the Russian Academy of Sciences.

1967-1969 postgraduate studies at the A. F. Ioffe Physical-Technical Institute of the Russian Academy of Sciences.

Achievement:

He defended his dissertation for the academic degree of a candidate of physical and mathematical sciences on the topic “Pyzogalvanomagnetic phenomena in the transition region of semiconductor doping at low temperatures”, Leningrad, 1970.

He defended his dissertation for the degree of doctor of physical and mathematical sciences on the topic “Interactions of impurities in diamond-like semiconductors and the physical basis for growing high-resistivity homogeneous structures from the liquid phase”, A. F. Joffe Physical-Technical Institute of the

Russian Academy of Sciences, Leningrad, 1983.

1985 - professor, speciality “Physics of semiconductors and dielectrics”.

In 2002, Saidov A.S. was included in the International encyclopedia of crystallography.

Decree of the President of the Republic of Uzbekistan No. UP-3912 August 23, 2007 “On awarding State Prizes of the Republic of Uzbekistan 2007 in the field of science and technology, literature, art, and architecture” for internationally recognized fundamental research, for the work “New semiconductor solid solutions and impurity effects of semiconductors” Laureate of the State Prize of the Republic of Uzbekistan.

Saidov Amin Safarbaevich is a famous physicist in the field of semiconductor materials. He created the concept “On the existence of a new class of semiconductor continuous substitutional solid solutions and the prospects for their application.” This concept theoretically and experimentally determined the possibility of the new solid solutions formation due to the substitution of molecules or even polyatomic complexes of the second component. When considering solid solutions for developing the concept, the following ideas were put forward:

A) molecular elements C2, Si2, Ge2, Sn2, their combinations CGe, CSn, SiGe, SiSn, GeSn and more complex combinations of elements, formed under certain thermodynamic conditions and not observed on traditional state diagrams, are new chemical compounds.

B) new chemical compounds and solid solutions based on them are formed during low-temperature crystallization of epitaxial layers from the gas or liquid phase.

In order to predict new materials, a formula for solubility in multicomponent systems is proposed, on the basis of which the conditions for the formation of continuous substitutional solid solutions are formulated. These conditions imply the equality of the sums of valences and close values ​​of the sums of covalent radii of the atoms of the molecules of the solution-forming components.

During the development of this concept, a wide class of solid solutions was predicted:

(IV2)1-x(III-V)x, (IV2)1-x(II-VI)x, (IV2)1-x(I-VII)x, (IV-IV)1-x(III- V)x, (IV-IV)1-x(II-VI)x, (IV4)1-x(II-IV-V2)x, (2III,V)1-x, (II-IV-V2) x,(II-IV)1-x(III2)xV2, (I – VII group numbers in the periodic table of chemical elements), covering the entire range of fundamental properties of semiconductor materials, starting with the most narrow-gap (InSb)1-x(Sn)x to wide-gap super-hard diamond (C2)1-x(BN)x solid solutions. Of particular interest are the group of solid solutions in which substitution by polyatomic complexes occurs. This is due to the fact that during the formation of nanomaterials there are structural defects at the boundary between the nanocluster and the matrix. In this case, it is possible to create a material that does not contain such defects.

The possibility of growing hetero-epitaxial single-crystal diamond layers on a silicon substrate using intermediate layers of corresponding continuous solid solutions has been demonstrated.

Some possible solid solutions of silicon carbide are predicted. The growth of epitaxial layers and the stability of silicon carbide poly-types in the presence of impurities are considered on the basis of solubility and adsorption.

Based on the concept of molecular exchange of elementary semiconductors with III-V and II-VI compounds, he theoretically predicted and synthesized ten new classes of semiconductor graded-gap continuous solid solutions from liquid phase epitaxy on silicon substrates:

1-class IV1-x IVx: Si1-xGex, Si1-x Snx, Ge1-x Snx;

2nd class (IV2)1-x(АIIIВV)x: (Ge2)1-x(GaAs)x, (Si2)1-x(GaP)x, (Ge2)1-x(InP)x, (Sn2) 1-x(InSb)x, (Si2)1-x(GaSb)x, (Si2)1-x(GaAs)x;

3rd grade; (IV₂)_1-x(А^IIВ^VI)_x: (Ge₂)_(1-x)(CdTe)_x, (Ge₂)_1-x(ZnSe)_x, (Si₂)_1-x(ZnS)_x, (Si₂)_1-x(CdS)_x, (Si₂)_1-x(ZnSe)_x; (Si₂)_1-x(GaN)_x.

4th grade; (IV2)1-x-y(АIIIВV)x(АIIВVI)y: (Ge2)1-x-y(GaAs)x(ZnSe)y, (ZnSe)1-x-y(Si2)x(GaP)y.

5th grade; (AIIIBV)1-x(AIIBVI)x: (GaAs)1-x(ZnSe)x.

6th grade; (IV2)1-x-y(IV)x (AII BVI)y-(Si2)1-x-y(Sn2)x(ZnS)y

7th grade; (IV2)1-x-y(IV2)x(IV2)y(Si2)1-x-y(Sn2)x(Ge2)y

8th grade; (IV2)1-x-y(AIII BV)х(АIIВVI)y(Ge2)x(GaAs)x(ZnSe)y

9th grade; (IV2)1-x-y-z(IV2)x(AIIIBV)y(AIIBVI)z(Si2)1-x-y-z(Ge2)x(GaAs)y(ZnSe)z

10th grade; (IV2)1-x-y-z-θ(IV2)x(IV2)y(AIIBV)2(AIIBVI)(Si2)1-x-y-z-θ(Ge2)x(Sn2)y(GaAS)z(ZnSe)θ 24 new graded-gap solid solutions, of which 90% are on silicon (Si) substrates, 5% are on germanium (Ge) substrates, and 5% are on gallium arsenide (GaAs) substrates.

The possibility of using part of the predicted silicon-containing solid solutions as buffer layers in the development of highly efficient monolithic cascade solar cells based on silicon is substantiated. Another part of them is proposed for the development of thin-film solar cells. Solid solutions have also been proposed for the development of photovoltaic cells for thermophotovoltaic systems that convert thermal radiation from sources into electricity.

The degree of crystalline perfection, electrical, photoelectric and optical properties of the grown solid solutions were determined.

The patterns of distribution of solid solution components over the thickness of the grown layers were determined depending on the technological conditions that made it possible to obtain graded-gap solid solutions with a given concentration gradient. The following hetero-structures pSi-n(Ge2)1-x(GaAs)x, pSi-n(Si2)1-x(ZnSe)x, pSi-n(Si2)1- x(CdS)x, рSi-n(Si2)1-x(GaP)x, рSi-n(Ge2)1-x(InSb)x, рSi-n(Si2)1-x(ZnS)x, рSi- n(Si2)1-x(CdTe)x pSi-(Si2)1-x(InP)x,pSi-(Si2)1-x(GaN)x on a germanium substrate Ge-(Ge2)1-x(GaAs) x on a gallium arsenide substrate GaAs-(Ge2)1-x(ZnSe)x, on a gallium phosphide substrate GaP-(Si2)1-x-y(GaP)x(ZnSe)y. The electrical and photoelectric properties of the resulting hetero-structures were determined. The features of the crystalline perfection of the boundaries of hetero-structures and the smoothing of the lattice parameter of the components and the formation of suitable buffer layers between the substrate and the solid solution have been elucidated.

Energy levels of molecules - Si2, Ge2, GaP, located inside the band gap of a wider-gap semiconductor compound АIIIВV and АIIВVI, as well as levels of molecules - GaAs, CdS, ZnSe, located inside the valence band of a narrower-gap semiconductor material were discovered.

For the first time in world practice, using an environmentally friendly method - melting in a solar furnace, silicon with a purity of 99.9% was obtained from metallurgical silicon with a purity of 96%, and for the first time discovered thermal and photothermal effects in purified technical silicon (99.9%) and in new solid solutions. Currently, professor Amin Saidov is engaged in the synthesis of new solid solutions on silicon substrates with quantum dots and quantum wells and the growth of hetero-structures by liquid-phase epitaxy, which can be used to create photovoltaic cells operating in the wavelength range of 0.545–1 microns, at a temperature range of 70- 80 °C and LEDs of red, yellow and blue as well as white light based on them.

Scientific publications:

3 monographs, 1 collection of articles, more than 280 scientific articles and 40 patents. Under his leadership, 12 candidates of sciences and 2 doctors of sciences were defended themselves.

e-mail: amin@uzsci.net