Multiserial Structure of Excitonic Energy Spectrum in Monoclinic ZnP2 Crystal

Autor: Oleg A. Yeshchenko, M. M. Bilyi, Igor Dmitruk, I. S. Gorban
Rok vydání: 1998
Předmět:
Zdroj: physica status solidi (b). 207:171-181
ISSN: 1521-3951
0370-1972
Popis: One-photon excitonic absorption spectra of the monoclinic ZnP 2 (β-ZnP 2 ) crystals are analysed. There exist four series characterized by the serial law E n = E g - Ry/n 2 + Δ/n 3 with the same value of energy gap Eg = 1.6026 meV. By variational calculations of the exciton energy dependence on the anisotropy parameter, we conclude an appearance of several hydrogen-like series caused by the splitting of excitonic states with different quantum numbers l and |m| due to the low symmetry of the crystal. Conclusions are made that two series with Δ = 0 can be attributed to the P-states of an exciton, and two others with Δ ¬= 0 to the S-states of an exciton. Calculations of e-h exchange interaction in an S-exciton are performed. Splitting of the series with Δ ¬= 0 is interpreted to have exchange origin (ortho-para-splitting). Its value is obtained to be 12.7 meV.
Databáze: OpenAIRE
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