Figure 1

(Color online) (a) TI-PL spectra of the $2.6\mathrm{nm}$ thick $\mathrm{Ga}\mathrm{N}∕{\mathrm{Al}}_{0.05}{\mathrm{Ga}}_{0.95}\mathrm{N}$ QW measured at $10\mathrm{K}$ for different excitation power densities in semilogarithmic scale (the excitation powers in microwatts are reported in the figure). (b) Comparison between PL and PLE spectra measured at $10\mathrm{K}$. (c) Comparison of the X and BX TR-PL intensities in logarithmic scale. The line is the square of the X TR-PL intensity scaled in order to fit with the BX data.Reuse & Permissions

Figure 2

(Color online) TI-PL spectra of the $2.6\mathrm{nm}$ thick $\mathrm{Ga}\mathrm{N}∕{\mathrm{Al}}_{0.05}{\mathrm{Ga}}_{0.95}\mathrm{N}$ QW measured at different temperatures for a power density of $20\mathrm{W}∕{\mathrm{cm}}^2$ in a linear scale. Inset: semilogarithmic plot of the ratio between the square of the integrated PL intensity at the X band divided by the BX integrated PL intensity as a function of $1∕k_{B}T$.Reuse & Permissions

Figure 3

(Color online) (a) Image of the TR-PL of the $2.6\mathrm{nm}$ thick $\mathrm{Ga}\mathrm{N}∕{\mathrm{Al}}_{0.05}{\mathrm{Ga}}_{0.95}\mathrm{N}$ QW measured at $T=10\mathrm{K}$ and at a power density of $20\mathrm{W}∕{\mathrm{cm}}^2$ under nonresonant excitation at $267\mathrm{nm}$, as measured by the streak camera apparatus. (b) TR-PL spectra at different time delays with time steps reported in picoseconds, in semilogarithmic scale. The line is a guide to the eye. (c) Decays of the exciton and biexciton emissions in semilogarithmic scale. The square of the excitonic emission is also reported for comparison.Reuse & Permissions

Figure 4

(Color online) (a) Image of the resonant TR-PL of the $2.6\mathrm{nm}$ thick $\mathrm{Ga}\mathrm{N}∕{\mathrm{Al}}_{0.05}{\mathrm{Ga}}_{0.95}\mathrm{N}$ QW measured at $T=10\mathrm{K}$ and at a power density of $20\mathrm{W}∕\mathrm{cm}$[2] under resonant excitation at $348\mathrm{nm}$, as measured by the streak camera apparatus. (b) Comparison of the BX time evolution for resonant and non resonant excitation, in linear scale. The energy shift (squares) of the X line under nonresonant excitation is also shown together with an exponential fit (dotted line). (c) Comparison of the X time evolution for resonant and nonresonant excitations in linear scale. The resonant decay corresponds to a detection energy $4\mathrm{meV}$ below the laser excitation.Reuse & Permissions