Phase diagram and specific band gap features of novel TlGaSe2: Zn+2(Cd+2, Hg+2) crystals.

Abstract In the present work, we investigate, in detail, the phase diagrams of the TlGaSe 2 –Zn(Cd,Hg)Se systems, which are quasi-binary and eutectic type. The solid phase solubility on the basis of components did not exceed 5 mol% at 670 K. The crystals of TlGaSe 2 : Zn+2(Cd+2, Hg+2)) solid solutions were prepared by Bridgman-Stokbarger method. It was established that the doping of Zn+2, Cd+2, Hg+2 leads to a slight decrease in the values of both the direct and indirect band gap energies with respect to the that in undoped TlGaSe 2 crystal. The temperature dependence of the band gap values for all the synthesized compounds is crucial for semiconductor applications. Also, the dominant mechanisms are proposed that contribute to the fundamental absorption edge tailing. Graphical abstract Image 1 Highlights • High quality TlGaSe 2 crystals, doped by Zn+2 or Cd+2 or Hg+2 crystals has been successfully growth for first time. • Single crystals were grown using a horizontal version of Bridgman -Stokbarger method. • Doping decrease of both the direct and indirect band gap energy with respect to the undoped TlGaSe 2 crystal. • Phase diagrams of the TlGaSe 2 –Zn(Cd)Se systems were investigated by DTA, XRD and microstructure analysis. [ABSTRACT FROM AUTHOR]