Effect of growth temperature of initial AlN buffer on the structural and optical properties of Al-rich AlGaN

Reducing dislocations of Al-rich AlGaN by combining AlN buffer and AlN/Al0.8Ga0.2N superlattices

“…3(b). It is deduced that the tilt (DQ R ) and lateral coherent length (DQ [ larger than the (0 0 0 2) FWHM ( ¼ 173 arcsec) of sample A, and the lateral coherent length of 365 nm, which is comparable to our early results by Williamson-Hall plots [25]. As a result, the tilt broadening plays a dominant role over the lateral coherence length one in our Al-rich AlGaN.…”

“…Furthermore, deep level transitions peaked at 306 nm and much deeper in sample A are greatly suppressed in comparison with that in sample B. It is commonly accepted that point defects such as V III and V III complexes or dislocations like edge TDs are responsible for the deep level transitions [25,26]. From early studies, it can be supposed that the 306 nm peak is due to single charged (V III complex) 1À related transition.…”

Origins and suppressions of parasitic emissions in ultraviolet light-emitting diode structures

“…Considering that the threading dislocation (TD) density in AlN buffer is high and is generally reduced in the upper AlGaN and AlN films grown in high temperature, P I may be the emission related to the TDs. 12 All the emissions mentioned previously are associated with either MQWs or defects that have close relation to the crystalline quality of the structure and the carrier confinement in the MQWs.…”

Characteristics of silent B1H mode in AlxGa1−xN alloys observed by Raman scattering

“…Fully relaxed AlxGa1−xN alloys with the thickness of 500 nm were grown on 400 nm thick AlN buffer on (0 0 0 1) sapphire substrates by low-pressure metalorganic chemical vapor deposition (LP-MOCVD) [12]. Their Al compositions were 31.5%, 45.8% and 63.7%, determined by high-resolution X-ray diffraction (HRXRD).…”