Aluminum-free nitride laser diodes: waveguiding, electrical and degradation properties

An aluminum-free nitride laser diode (LD) operating at a wavelength of λ = 452 nm with a threshold current density of jth = 4.2 kA/cm2 grown by plasma assisted molecular beam epitaxy is demonstrated. Aluminum is successfully eliminated from the cladding layers and the electron blocking layer. The lifetime of the devices with and without aluminum are studied. It is found that aluminum, which is highly susceptible to oxidation, has no influence on the degradation mechanism of nitride optoelectronic devices. Furthermore, comprehensive theoretical calculations are presented to show the impact of removal of aluminum from the structure on LD properties.