TY - JOUR

T1 - Structural and dynamic properties of short-period GaN/AlN superlattices grown by submonolayer digital epitaxy

AU - Davydov, V. Yu

AU - Roginskii, E. M.

AU - Kitaev, Yu E.

AU - Smirnov, A. N.

AU - Eliseyev, I. A.

AU - Yagovkina, M. A.

AU - Nechaev, D. V.

AU - Jmerik, V. N.

AU - Smirnov, M. B.

N1 - Funding Information: The work was supported in part by Russian Foundation for Basic Research (project RFBR-BRICS №17-52-80089). XRD characterizations were performed using equipment of the Federal Joint Research Center “Material science and characterisation in advanced technology” sponsored by the Ministry of Education and Science of the Russian Federation. Publisher Copyright: © Published under licence by IOP Publishing Ltd. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/12/17

Y1 - 2020/12/17

N2 - Structural and dynamic properties of short-period GaN/AlN superlattices with the thicknesses of the constituent layers varying from two to several monolayers, grown using the method of submonolayer digital molecular beam epitaxy, are experimentally and theoretically studied. It is established that in the grown samples there are two types of periodicity. One type is formed by periodic sequence of GaN and AlN layers in the superlattice, and the second one is related with periodic interruptions in the growth of superlattice for the evaporation of excess Ga metal. The dependences of the positions and intensities of the lines in the Raman spectra on the period of the superlattice are determined, and microscopic nature of optical phonon modes is established. The doublet structure of the E(TO) lines localized in the GaN and AlN layers of superlattice, genetically related to the E 2(high) and E1 phonon branches of the bulk crystal, is first discovered and explained. A strong dependence of the polar modes localized in the AlN layer on the thickness of layer forming the superlattice is revealed. The results of complex studies will improve the accuracy of quantitative estimation of important parameters of superlattice structures and can be used to optimize growth parameters for the fabrication of structurally perfect short-period GaN/AlN superlattices.

AB - Structural and dynamic properties of short-period GaN/AlN superlattices with the thicknesses of the constituent layers varying from two to several monolayers, grown using the method of submonolayer digital molecular beam epitaxy, are experimentally and theoretically studied. It is established that in the grown samples there are two types of periodicity. One type is formed by periodic sequence of GaN and AlN layers in the superlattice, and the second one is related with periodic interruptions in the growth of superlattice for the evaporation of excess Ga metal. The dependences of the positions and intensities of the lines in the Raman spectra on the period of the superlattice are determined, and microscopic nature of optical phonon modes is established. The doublet structure of the E(TO) lines localized in the GaN and AlN layers of superlattice, genetically related to the E 2(high) and E1 phonon branches of the bulk crystal, is first discovered and explained. A strong dependence of the polar modes localized in the AlN layer on the thickness of layer forming the superlattice is revealed. The results of complex studies will improve the accuracy of quantitative estimation of important parameters of superlattice structures and can be used to optimize growth parameters for the fabrication of structurally perfect short-period GaN/AlN superlattices.

UR - http://www.scopus.com/inward/record.url?scp=85098321581&partnerID=8YFLogxK

U2 - 10.1088/1742-6596/1697/1/012155

DO - 10.1088/1742-6596/1697/1/012155

M3 - Conference article

AN - SCOPUS:85098321581

VL - 1697

JO - Journal of Physics: Conference Series

JF - Journal of Physics: Conference Series

SN - 1742-6588

IS - 1

M1 - 012155

T2 - International Conference PhysicA.SPb 2020

Y2 - 19 October 2020 through 23 October 2020

ER -