Figure 5. Comparison between experimental and theoretical relaxation times in MEG.

(a) Experimental hot-carrier relaxation times versus substrate temperature for MEG samples with ∼63 and ∼35 layers. The values correspond to the long relaxation times from Fig. 2e,f. (b) Theoretical hot-carrier relaxation times versus substrate temperature calculated using the linearized interlayer Coulombic energy transfer rate equation (12). The interlayer Coulombic energy transfer mechanism explains relaxation time trends versus substrate temperature and multilayer system thickness. The factor-of-two discrepancy in magnitude is typical for RPA theories of electron-electron scattering amplitudes. The level of agreement found here is similar to that found in comparisons of RPA calculations and measurements of the Coulomb-coupled interlayer momentum transfer rate (that is, Coulomb drag resistivity) between neighbouring GaAs/AlGaAs quantum wells54.