Analysis of Some Structural, Electronic and Optical Properties of ZnnTen (n=1, 7, 11, 13) Nanostructures: A DFT/TD-DFT Study

Some of the structural properties, electronic properties and UV-Vis spectra of zinc telluride diamondoids nanostructures ZnnTen (n=1, 7, 11 13) have been investigated theoretically by using the Gaussian 09 package, density functional theory and time-dependent density functional theory at the B3LYP level with SDD (Stuttgart-Dresden pseudopotentials) basis function. The structural properties showed that the average Zn-Te bond length of all diamondoids converged to the experimental value 2.406 angstrom and hexamantane Zn13Te13 has the longest bond length of 2.705 angstrom. Binding energy per atom indicated that the tetramantane Zn11Te11 more stable than other diamondoids because it has the largest binding energy of 2.352 eV/atom and the smallest ratio of dangling to total bonds. The energy gap decreased with increasing in diamondoids size and tend to touch the practical value 2.26 eV, hexamantane Zn13Te13 has an energy gap equal to 2.56 eV. UV-Vis spectra for tetramantane Zn11Te11 and hexamantane Zn13Te13 refer to redshift with an increased size of diamondoids. Tetramantane Zn11Te11 has a maximum peak at 345.6 nm and 410.4 nm for hexamantane Zn13Te13. These results refer to the ability to control the ZnTe properties by varied diamondoids sizes. These lead to wide applications in different fields such as optoelectronic devices, photoelectronic devices, detectors, and sensors.