Comparison study of energy bands and Wannier-Mott excitons in mixed Zn(P1-xAsx)2 and Zn1-xCdxP2 crystals
O. A. Yeshchenkoa, M. M. Biliy and Z. Z. Yanchuk
Physics Department, Taras Shevchenko National Kyiv University, 6 Akademik Glushkov prosp., 03127 Kyiv, Ukraine
Corresponding author: a firstname.lastname@example.org
Published online: 9 July 2002
Excitonic absorption, reflection and photoluminescence spectra of mixed Zn(P1-xAsx)2 crystals over the full range of x () and Zn1-xAsxCdxP2 crystals at have been studied at low temperatures (1.8 K). The decrease of the energy gap in Zn(P1-xAsx)2 at the increase of x occurs slightly sublinearly. The rydbergs of excitonic series in this crystals decrease as well, and the dependences Ry(x) for all series are strongly superlinear at small x. In Zn1-xCdxP2 crystals the energy gap and rydbergs decrease at the increase of x (at ) as well. The dependences of Eg and Ry on x are considerably stronger in Zn(P1-xAsx)2 than in Zn1-xCdxP2. At the increase of x the half-width of excitonic absorption lines increases monotonically in both type crystals that is evidence of the increasing role of fluctuations of crystal potential.
PACS: 71.35.-y – Excitons and related phenomena / 74.62.Dh – Effects of crystal defects, doping and substitution
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2002