Room-Temperature Continuous-Wave Electrically Driven Semipolar (202̅1) Blue Laser Diodes Heteroepitaxially Grown on a Sapphire Substrate

Abstract

Growth of semipolar GaN laser diodes (LDs) on low-cost and large-size foreign substrates is crucial yet remains very challenging. In this study, we report the world's first continuouswave (CW) electrically driven semipolar blue LDs at room temperature heteroepitaxially grown on a 4-in. sapphire substrate. The semipolar (202̅ 1) GaN material grown on sapphire substrate exhibits high crystal quality from the X-ray diffraction and transmission electron microscopy measurements. The AlGaNcladding free semipolar blue LDs utilizing thin p-GaN/indium tin oxide (ITO) cladding structure show a lasing peak at 456 nm, a threshold current density of 6.1 kA/cm 2 , and a high output power (P 0 ) of 1.03 W at 2.8 A under pulsed operation condition. Moreover, the semipolar blue LDs exhibit a CW P 0 of 243 mW at room temperature. The emission light from the semipolar blue LDs is 100% polarized. These results mark a significant breakthrough in substantially reducing the cost of semipolar LDs and expediting the development of future semipolar GaN LDs and their applications.

Plasma assisted molecular beam epitaxial growth of GaN with low growth rates and their properties

“…[1][2][3] Although metal organic chemical vapor deposition (MOCVD) is overwhelming in the III-nitride device markets, plasma assisted molecular beam epitaxy (PA-MBE) is another important epitaxy technique to grow III nitride materials and devices. [4][5][6][7][8][9][10][11] Compared to MOCVD, MBE has some advantages, such as an ultrahigh vacuum and ultra-clean environment for growth with low impurity levels, precise control of epilayer thickness, atomic level sharp interfaces, hydrogen free environment for automatic activation of Mg acceptors, and high indium content alloys at relatively low temperatures. Especially, MBE is suitable for growing devices with sophisticated fine structures and quantum effect structures, thanks to its much faster source supply switch ability.…”

Numerical Investigation into Optoelectronic Performance of InGaN Blue Laser in Polar, Non-Polar and Semipolar Crystal Orientation

“…Hence, several basic and applied disquisitions on non-c-plane-oriented growth of GaN and InGaN have been reported over the last few years thanks to plasma-assisted Molecular Beam Epitaxy (MBE) and Metal-Organic Chemical Vapor Deposition (MOCVD). Semipolar (112 ̅ 2) and (2021 ̅̅̅ )-oriented blue laser diodes grown on sapphire substrate and lasing at peak wavelength of 439 and 456 nm were reported for the first time [10,11]. The optical properties of non-polar m-plane InxGa1-xN (x ≤ 0.21) thin films have been characterized by Cao et al via photoluminescence spectroscopy [12].…”