Specific Features of Content Dependences for Energy Gap in InxTl1-xI Solid State Crystalline Alloys |
| A.I. Kashuba a, M. Piasecki b, O.V. Bovgyra a, V.Yo. Stadnyk a, P. Demchenko c, A. Fedorchuk d, A.V. Franiv a and B. Andriyevskye
aPhysics Faculty, Ivan Franko National University of Lviv, Kyrylo and Mephodiy str. 8a, Lviv, 79005, Ukraine bInstitute of Physics, Jan Długosz University Częstochowa, Armii Krajowej 13/15, Częstochowa, Poland cDepartment of Inorganic Chemistry, Ivan Franko National University of Lviv, Kyryla and Mephodiy Str. 6, Lviv, 79005, Ukraine dDepartment of Inorganic and Organic Chemistry, Lviv National University of Veterinary Medicine and Biotechnologies, Pekarska Str. 50, 79010 Lviv, Ukraine eFaculty of Electronics and Computer Sciences, Koszalin University of Technology, Śniadeckich 2, PL-75453, Koszalin, Poland |
| Received: September 24, 2017; In final form: November 15, 2017 |
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| A series of InxTl1-xI (x=0.4-0.9) single crystalline solid state alloys were successfully synthesized by the vertical Bridgman method. For the first time the density functional theory based band structure calculations are performed and features of the band energy dispersion are discussed. Comparison with the experimental energy gap Eg obtained from the optical photoconductivity is discussed. An essential role of the localized defects and excitons in formation of the edge photoconductivity is analyzed. Relation between the crystal structure and photoconductivity of the materials studied is discussed. Also the origin of the principal valence and conduction bands is explored. Experimental measurements of the band gap Eg by the optical and photoconductivity methods have given opposite dependences with respect to the indium content x. Features of the photoconductivity spectra for different crystallographic directions have been discussed with taking into account the chemical bonds anisotropy. |
DOI: 10.12693/APhysPolA.133.68 PACS numbers: 71.20.Nr, 71.20.-b, 42.70.Gi, 71.35.-y |