Synthesis and Properties of Indium Antimonide Big Quantum Dots
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sis and Properties of Indium Antimonide Big Quantum Dots D. V. Krylskya* and N. D. Zhukovb a
Scientific Research Institute of Applied Acoustics, Dubna, Moscow oblast, 141980 Russia b LLC Volga Research and Production Enterprise, Saratov, 410033 Russia *e-mail: [email protected] Received April 27, 2020; revised June 10, 2020; accepted June 10, 2020
Abstract—Colloidal chemistry techniques at elevated temperatures (250–300°C) have been used to synthesize big (up to 20 nm) quantum dots (QDs) based on indium antimonide (InSb). In respect to their optical and electrical characteristics, the obtained big QDs exhibit properties similar to those of QDs with usual dimensions (4–5 nm), except the spectral maximum of luminescence being shifted inadequately to the size difference. This circumstance, together with the QD shape as measured by transmission electron microscopy, can be indicative of a less perfect crystalline structure of obtained big QDs, probably resulting from insufficiently high temperature of synthesis. Keywords: colloidal quantum dots, indium antimonide, synthesis, luminescence, current–voltage characteristics. DOI: 10.1134/S1063785020090205
The synthesis and properties of colloidal semiconductor quantum dots (QDs) have been studied for about two decades, but most investigations were devoted to wide-bandgap cadmium chalcogenides and medium-bandgap lead chalcogenides [1]. The prospects of expanding the application of QDs in electronics are related primarily with extending the research into infrared (IR) and terahertz (THz) spectral ranges, where narrow-gap and gapless semiconductors are required [2]. In this respect, A3B5 semiconductor compounds are of interest for possessing the broadest spectrum of properties, showing the best quantumconfinement characteristics, and offering a wide choice to meet diverse requirements. Indium antimonide (InSb) is a well-known representative of A3B5 semiconductors. InSb is characterized by extremely small effective masses of electrons and holes. This determines the relatively large radius of the Bohr exciton (up to 60 nm) [3, 4], which accounts for an important practical advantage—the large size of QDs, in which a regime of strong quantum confinement of carriers (rather than exciton quantization as a whole) can be realized. However, an increase in QD size can also lead to a growing probability of structural lattice distortion during synthesis and, hence, weakening of the quantum confinement effects. The fundamental and applied interest in big QDs is related to the fact that many important manifestations of physical phenomena are determined by the states and behavior of quasiparticles (excitons, plasmons,
etc.) and domains characterized by a wide interval of micron and submicron dimensions [5]. The transition from micro- to nanoscale would provide for the extension of technology to the THz range. The above circumstances make the synthesis and characterization of big (up to 20 nm) indium antimonide quantum dots (InSb-big QDs) an important and interesting task. The published info
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