Fig. 1. PL spectra of sample H₂-MQW and sample N₂-MQW, recorded at room temperature with the 375 nm laser (5 μW), with fitted smooth lines to eliminate the oscillation pattern originating from thin-film interference

Fig. 2. (a) and (b) present the PL spectra of sample N₂-MQW and sample H₂-MQW, respectively, recorded at varied laser powers, and the insets depict how the PL spectra were smoothly fitted to eliminate oscillating interference pattern when taking the spectral data at 3.46 mW as examples; (c) exhibits the peak energy dependence of the PL spectra on the excitation power for the two samples, and (d) illustrates the spectral width dependence of their PL spectra on the excitation power

Fig. 3. Variation of the PL spectral characteristics of the H₂-MQW and N₂-MQW samples with respect to temperature
(a): Depicts the dependence of peak energy on temperature;(b): Depicts the dependence of integrated peak intensity on temperature (the solid lines are the fitting results obtained with the Arrhenius formula)

Fig. 4. The time-resolved PL spectra of the H₂-MQW and N₂-MQW samples recorded at (a) 4 K and (b) 300 K, respectively, with the measured wavelength set to the peak wavelength of the PL spectra at the corresponding temperatures. The spectra of the same temperature have been normalized, and the solid lines are the fittings to the decaying lifetimes