Demonstration of 426 nm InGaN/GaN Laser Diodes Fabricated on Free-Standing Semipolar (11\bar22) Gallium Nitride Substrates

Abstract

Semipolar (1122) plane III–nitride laser diodes (LDs) were realized on low extended defect density semipolar (1122) GaN bulk substrates. The LD structures were grown by conventional atmospheric-pressure metal organic chemical vapor deposition (MOCVD), using conditions similar to that of c-plane nitride device growth. The mirror facet for a laser cavity was formed by dry-etching of III–V nitride films without cleaving. Stimulated emission was observed at 426.9 nm with a full width at half maximum (FWHM) of less than 1 nm. The (1122) plane laser diode had threshold currents (Ith) of 306 mA, corresponding to a threshold current densities (Jth) of 12.8 kA/cm2.

InGaN-based true green laser diodes on novel semi-polar GaN substrates

“…While cw operation of m-plane LDs at 499.8 nm has been reported recently [5], an issue of the stacking fault formation has been pointed out in the green emitting region [12]. Lasing wavelengths of LDs on the semi-polar f1 1 2 2g plane also have not exceeded 426.9 nm [9], whereas stimulated emission at 514 nm by optical pumping has been demonstrated [13]. An issue that is more influential than the internal electric field problem is to fabricate high quality green InGaN QWs.…”

“…However, lasing at even longer wavelengths is believed to be difficult owing to their large internal electric fields, which reduce the radiative recombination probability within the quantum wells (QWs) especially at longer wavelengths [3,4]. In order to circumvent these problems, the employment of non-or semi-polar planes such as the f1 0 1 0g (m-plane) [5][6][7], f1 0 1 1g plane [8], f1 1 2 2g planes [9], and others [10,11] has been actively explored. While cw operation of m-plane LDs at 499.8 nm has been reported recently [5], an issue of the stacking fault formation has been pointed out in the green emitting region [12].…”

Microstructure investigation of semi-polar (11-22) GaN overgrown on differently designed micro-rod array templates

“…So far, all the semi-polar III-nitride laser structures have been grown exclusively on extremely expensive free-standing semi-polar GaN substrates. 1,8,9 Therefore, it implies that it is necessary to further improve the crystal quality of any overgrown (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)) GaN on sapphire in order to achieving lasing. In this paper, by carefully designing micro-rod templates used for our overgrowth, in particular, the diameter and height of the micro-rods used (two major parameters), we have achieved (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) semi-polar GaN with best crystal quality on sapphire, which has been systematically studied as a function of the micro-rod parameters by means of multiple characterization methods including photoluminescence (PL), transmission electron microscopy (TEM) and X-ray diffraction (XRD).…”

Blue InGaN/GaN laser diodes grown on (33$ \bar 3 \bar 1 $) free‐standing GaN substrates

“…Stimulated emission wavelength in nonpolar LDs has so far been limited to 500 nm due to a degradation in the structural quality of high indium content m-plane InGaN QWs [5,6]. Various semipolar planes have also been investigated for longwavelength LDs [7,8]. The most notable semipolar achievements to date have been reported for LDs grown on semipolar (2021) free-standing GaN substrates [9][10][11].…”