How to obtain metal-polar untwinned high-quality (1 0 −1 3) GaN on m-plane sapphire

Aluminium incorporation in polar, semi- and non-polar AlGaN layers: a comparative study of x-ray diffraction and optical properties

“…Growth parameters of these templates are reported elsewhere 30 . To produce an Al-polar () AlN template, about 10-nm-thick () AlN layer was initially sputtered onto a 2-inch m -plane sapphire wafer using directional sputtering 33 . Afterwards, this wafer was loaded into the reactor chamber to grow a 300-nm-thick AlN layer at a surface temperature of 1290°C.…”

“…Even though semipolar () AlN templates can be grown on m -plane sapphire 16 , crystal twinning has been observed for the layers that might lead to difficulties for AlGaN growth and composition determination. Recently, we have successfully produced untwinned semipolar () AlN templates on m -plane sapphire using directional sputtering 33 . Therefore, to extend compositional study of AlGaN with different surface orientations, in this paper, we report on MOVPE-growth of Al x Ga 1− x N layers simultaneously on polar (0001), semipolar () and (), as well as nonpolar () and () AlN/sapphire templates over the entire range of composition.…”

Simultaneous Growth of Various InGaN/GaN Core‐Shell Microstructures for Color Tunable Device Applications

“…After the QWs growth calibration, we investigated the influence of the surface orientation of the substrate on the QWs color emission. To obtain pure polar and non‐polar data, we co‐loaded un‐patterned (0001) and (10‐10) GaN templates, the latter grown on a sputtered AlN on sapphire in the MOCVD reactor . Assuming similar In incorporation, the QWs grown on (10. l ) semi‐polar orientation would have an emission wavelength shorter than polar but longer than non‐polar orientations.…”

Effect of High-Temperature Nitridation and Buffer Layer on Semi-Polar (10–13) AlN Grown on Sapphire by HVPE

“…However, the strong spontaneous and piezoelectric polarization along c-axis will weaken the recombination of carriers in the quantum wells [4], which in turn decrease the luminescence efficiency of devices. The use of semi-polar substrates and epitaxial layers [5][6][7][8][9], such as (10)(11), (10)(11)(12) and (10-13) AlN, can effectively solve this problem since the polarization field is greatly weakened [10,11]. According to the energy band structure, other semi-polar plane, such as (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22), can produce a negative polarization field across multiple quantum wells used in optoelectronic devices, which can reduce the confinement of hole states and increase the carrier loss.…”

“…The use of semi-polar substrates and epitaxial layers [5][6][7][8][9], such as (10)(11), (10)(11)(12) and (10-13) AlN, can effectively solve this problem since the polarization field is greatly weakened [10,11]. According to the energy band structure, other semi-polar plane, such as (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22), can produce a negative polarization field across multiple quantum wells used in optoelectronic devices, which can reduce the confinement of hole states and increase the carrier loss. In contrast, the (10-13) plane has a positive polarization field, which is favorable for the devices [12].…”