Optical Properties of CdMnTe Film: Experimental and Theoretical Aspects

Authors H. Ilchuk , E. Zmiiovska , R. Petrus , I. Semkiv , I. Lopatynskyi, A. Kashuba

Lviv Polytechnic National University, S. Bandera St., 12, 79013 Lviv, Ukraine

Issue Volume 12, Year 2020, Number 1
Dates Received 11 November 2019; revised manuscript received 15 February 2020; published online 25 February 2020
Citation H. Ilchuk, E. Zmiiovska, R. Petrus, et al., J. Nano- Electron. Phys. 12 No 1, 01027 (2020)
DOI https://doi.org/10.21272/jnep.12(1).01027
PACS Number(s) 52.70.K, 61.82.Fk
Keywords Quasi-close space sublimation, Thin films (60) , Band gap (29) , Transmission (16) , Optical function.  x  xxyz  .

CdTe thin films are representatives of AIIBVI crystal group and show semiconductor behavior. They are an important research field because of their wide applications in various fields of optoelectronic devices. A better opportunity to manage in a wide energy range the band gap Eg for practical applications exists with varying the content of CdTe-MnTe (from Eg  1.46 eV for CdTe to Eg  3.1 eV for MnTe). The titled compounds may be considered as a particular class of binary semiconducting compounds possessing promising optical parameters. Cd1 – xMnxTe films were prepared on mica substrates by closed-space sublimation of polycrystalline Cd0.88Mn0.12Te powders. X-ray diffraction studies revealed that the as-deposited films had a zinc blende structure with a preferential (111), (222) (333) and (444) orientations. Included Mn components cause the increase in the lattice parameters (compared with parent compound CdTe/mica). From EDS analysis it was observed that composition of the film was Cd0.96Mn0.04Te. The lattice parameter was refined by X-ray diffraction: a  0.6485(3) nm and V  0.2727(3) nm3. Results of study of transmission and reflection spectra of the Cd0.96Mn0.04Te films-substrate combinations are present. The transmission and reflection spectra of the films exhibit periodic oscillations associated with the substrate. The spectral dependence of the optical absorption of Cd0.96Mn0.04Te films in the (h)2 – h coordinates demonstrates the presence of the fundamental absorption edge. The value of the optical band gap of the Cd0.96Mn0.04Te films was found to be equal to 1.465 eV and formed by direct interband optical transitions. Within the framework of the pseudopotential method, the dynamics of changing the parameters of the electronic subsystem of the Cd1 – xMnxTe is theoretically studied. Using the Kramers-Kronig relations, the dielectric permeability, reflective index and reflectivity spectra that satisfactorily correlate with the experimental data are obtained.

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