Dielectric Function Theory Calculations of Polaritons in GaN
K.P. Korona, R. Stępniewski and J.M. Baranowski
Institute of Experimental Physics, Warsaw University, Hoża 69, 00-681 Warszawa, Poland
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Properties of polaritons (free excitons coupled with photons of similar energy) in gallium nitride are investigated by performing calculations based on dielectric function theory including all three excitons A, B and C (characteristic for the wurtzite structure). Moreover the excited states of excitons have been taken into account by adding Elliott's components to dielectric function. Energies, polarizabilities and damping constants of excitons are determined. It is shown that due to inter-exciton interactions the B and C excitons are strongly damped. It is estimated that the characteristic time of B to A relaxation is tBA=1 ps. The exciton C lifetime is estimated τC=0.2 ps.
DOI: 10.12693/APhysPolA.92.867
PACS numbers: 71.36.+c, 78.66.Fd