Photoluminescence properties of lamellar nano‐composites obtained by Cd intercalation of GaSe and GaSe:Eu single crystals

Abstract

In this work surface morphology, composition and photoluminescence at 293 K and 78 K, of composite obtained by intercalation of GaSe and GaSe:Eu (0.49 at.% and 1.00 at.%) single crystal lamellas with Cd from vapor phase at 753 K and 830 K are investigated. As‐obtained composite consists of CdSe and microstructured GaSe single crystallites. Photoluminescence spectrum of GaSe:Eu single crystal lamellas is composed of Eu3+ emission band 5D0 → 7F1, 5D0 → 7F2 and 5D1 → 7F3 transitions) and indirect exciton line in GaSe crystallites. Emission spectrum of single crystalline GaSe–CdSe composite, at 78 K and 293 K, consists of donor‐acceptor band in GaSe microcrystallites and emission band of CdSe crystallites. Composite derived from the intercalation of GaSe:Eu (0.49 at.%) single crystals with Cd exhibits strong visible luminescence. Its quasi‐continuous photoluminescence spectrum is produced by superposition of luminescent emissions of CdSe nano‐ and microparticles, and microstructured GaSe. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Optical and Photoelectric Properties of Nanolamellar Structures Obtained by Thermal Annealing of InSe Plates in Zn Vapours

“…The thermal annealing (TA) of gallium and indium monochalcogenides in normal atmosphere, or in oxygen‐enriched atmosphere, leads to the formation of their crystalline micro and nanocomposites with In 2 O 3 and Ga 2 O 3 oxides . As we demonstrated in our previous works, crystalline composites consisting of A II B VI and A III B VI semiconductors, with physical properties characteristic for these compounds, can be obtained by TA of the A III B VI (GaS, GaSe, GaTe and InSe) and semiconductors (e.g., Ga 2 S 3 ) in Cd and Zn vapours …”

“…These lamellae can be used as base elements in heterojunctions with optical contact, structures of semiconductor‐own oxide type and metal‐semiconductor contact . Both, the specifics of chemical bonds between the atoms of B‐A‐A‐B layered packings, and low density of surface states (≈10 10 cm −2 ), define the obtaining methods of 2D structures for nano‐lamellar electronic devices, ultrathin layer transistors, etc. The thermal annealing (TA) of gallium and indium monochalcogenides in normal atmosphere, or in oxygen‐enriched atmosphere, leads to the formation of their crystalline micro and nanocomposites with In 2 O 3 and Ga 2 O 3 oxides .…”

Method of smoothing photoluminescence spectra

“…The smoothed PL spectra are adduced in works [6][7][8], however information about the way of this smoothing is absent. The works [9][10] perform the decomposition of PL spectra on elementary bands by means of mathematical packages, but smoothing is not shown in details and even the used way of it is not mentioned. There is an opinion in the book [11], which is considered as one of basic sources on the problem of smoothing, that luminescent spectra must be smoothed by Savitzky-Golay method, using the window width that equals 11 or 25 points, and polynomials from quadratic to quintic inclusive.…”

Photoelectric and photoluminescence properties of CdTe–GaTe composite

“…Its single crystals are composed of layered atomic packings of Te–Ga–Ga–Te type with strong bonds of ionic‐covalent type inside packings and weak van der Waals polarization bonds between them . Packings are so disposed to one another that cracks are formed between them, in which atoms and molecules can easily intercalate . The van der Waals planes are free of dangling bonds and prove to be very inert to chemical reactions .…”