Temperature quenching of spontaneous emission in tunnel-injection nanostructures

The spontaneous-emission spectra in the near-IR range (0.8–1.3 $\mu$m) from inverted tunnel-injection nanostructures are measured. These structures contain an InAs quantum-dot layer and an InGaAs quantum-well layer, separated by GaAs barrier spacer whose thickness varies in the range 3–9 nm. The temperature dependence of this emission in the range 5–295 K is investigated, both for optical excitation (photoluminescence) and for current injection in $p$–$n$ junction (electroluminescence). At room temperature, current pumping proves more effective for inverted tunnel-injection nanostructures with a thin barrier ($<$ 6 nm), when the apexes of the quantum dots connect with the quantum well by narrow InGaAs straps (nanobridges). In that case, the quenching of the electroluminescence by heating from 5 to 295 K is slight. The quenching factor $S_\mathrm{T}$ of the integrated intensity $I$ is $S_\mathrm{T}=I_5/I_{295}\approx3$. The temperature stability of the emission from inverted tunnel-injection nanostructures is discussed on the basis of extended Arrhenius analysis.