Sublimation process and physical properties of vapor grown ?-In2Se3 platelet crystals

Title

Sublimation process and physical properties of vapor grown ?-In2Se3 platelet crystals

Creator

Ajayakumar C.J.; Kunjomana A.G.

Description

Indium selenide (?-In2Se3) crystals have been grown by the closed tube sublimation process in the absence of seed crystals and chemical transporting agents. The composition, structure and morphology of the samples grown under different vacuum conditions were examined by energy dispersive analysis, X-ray diffraction, and scanning electron microscope. Structural features of the crystals obtained in a vacuum of 10?3 mbar exhibited a few reflections not belonging to ? phase, whereas X-ray diffraction spectra of the crystals deposited under a vacuum of 10?6 mbar revealed evidence of sharp peaks with high intensities of ?-In2Se3 crystalline phase. When growth runs were performed for 72 h, voids were observed on the surface whereas for a duration of 120 h, platelet crystals were obtained. Optical properties of these samples were investigated using the FT-IR and photoluminescence spectroscopy. The average transmittance of the platelets in the visible and near infrared region of solar spectrum was found to be ?81% and an optical band gap of ?2.05 eV was computed from the transmission spectrum. Photoluminescence spectra of the grown In2Se3 crystals recorded at room temperature using an excitation laser of wavelength 355 nm showed a peak in the near band edge emission (NBE) corresponding to an energy of 2.01 eV. Under an illumination power of 12 mW/cm2, the photocurrent increased linearly with applied voltage and the dark current was found to be ~2.50?9 A for 10 V. These results suggest that the as-grown ?-In2Se3 platelets crystallized from vapor deposition, possess superior optoelectronic properties than the other phases for solar cell applications. 2016 Elsevier B.V.

Source

Journal of Crystal Growth, Vol-453, pp. 99-105.

Date

2016-01-01

Publisher

Elsevier B.V.

Subject

A1. Crystal morphology; A1. X-ray diffraction; A2. Growth from vapor; B2. Semiconducting indium compounds

Coverage

Ajayakumar C.J., Crystal Research Centre, Department of Physics, Christ University, Bengaluru, 560 029, India; Kunjomana A.G., Crystal Research Centre, Department of Physics, Christ University, Bengaluru, 560 029, India

Rights

Restricted Access

Relation

ISSN: 220248; CODEN: JCRGA

Format

Online

Language

English

Type

Article

Identifier

https://doi.org/10.1016/j.jcrysgro.2016.08.004

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