Fig. 1. Reflectance curve monitoring of three samples with different doping concentrations

Fig. 2. AFM images (5 µm×5 µm) of three samples with different doping concentrations

Fig. 3. X-ray spectra of three samples with different doping concentrations

Fig. 4. Cross-sectional scanning electron microscope image of the double-channel structure

Fig. 5. L-I-V curves of samples with different doping concentrations

Fig. 6. (a) L-I-V curves of the chip at different temperatures; (b) Wall-plug efficiency of the chip at different temperatures

Fig. 7. Threshold current density and characteristic temperature T₀ at different temperatures

Fig. 8. L-I-Vand spectra in continuous-wave operation at room temperature