Zinc oxide (ZnO) has

PHYSICS · Multi-part · Fermi University Physics · Condensed Matter, Materials & Soft Matter · Dielectric and optical properties of solids · Dielectric and optical properties of solids

Solid State Physics, Ch Optical properties: interband absorption, excitons and luminescence

Problem

Zinc oxide (ZnO) has, near its excitonic absorption resonance at

3.30\,\mathrm{eV}

at low temperature, optical constants

n_{\rm opt}=2.0

and

\kappa_{\rm opt}=0.05

. Its free-exciton binding energy is

E_b=60\,\mathrm{meV}

. ((a)) Estimate the absorption coefficient and the absorption depth at

3.30\,\mathrm{eV}

. ((b)) Estimate the highest temperature at which ZnO's free-exciton line could still be resolved, using

E_b\sim k_BT^*

, and compare with GaAs's

49\,\mathrm{K}

and with room temperature.

Browse the problem library