Green laser diodes with low threshold current density via interface engineering of InGaN/GaN quantum well active region

Kiratnia²,

et al. 2020

Crystals

Recently, InGaN grown on semipolar and non-polar orientation has caused special attraction due to reduction in the built-in polarization field and increased confinement of high energy states compared to traditional polar c-plane orientation. However, any widespread-accepted report on output power and frequency response of the InGaN blue laser in non-c-plane orientation is readily unavailable. This work strives to address an exhaustive numerical investigation into the optoelectronic performance and frequency response of In0.17Ga0.83N/GaN quantum well laser in polar (0001), non-polar (101¯0) and semipolar (101¯2), (112¯2) and (101¯1) orientations by working out a 6 × 6 k.p Hamiltonian at the Γ-point using the tensor rotation technique. It is noticed that there is a considerable dependency of the piezoelectric field, energy band gap, peak optical gain, differential gain and output power on the modification in crystal orientation. Topmost optical gain of 4367 cm−1 is evaluated in the semipolar (112¯2)-oriented laser system at an emission wavelength of 448 nm when the injection carrier density is 3.7 × 1018 cm−3. Highest lasing power and lowest threshold current are reported to be 4.08 mW and 1.45 mA in semipolar (112¯2) crystal orientation. A state-space model is formed in order to achieve the frequency response which indicates the highest magnitude (dB) response in semipolar (112¯2) crystal orientation.

Section: Resultsmentioning

confidence: 99%

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

Kiratnia²,

et al. 2020

Crystals

“…The highest wavelength reported for a GaN‐based LD is by Sumitomo Electric on semipolar

(20 \bar{2} 1)

with a lasing wavelength of 533.6 nm . Figure compares the threshold current density versus lasing wavelength for green LDs on c ‐plane and non‐basal substrates …”

Section: Successes and Challengesmentioning

confidence: 99%

A Decade of Nonpolar and Semipolar III-Nitrides: A Review of Successes and Challenges

Monavarian

Rashidi

Feezell

2018

Phys. Status Solidi A

The performance of III-nitride devices is degraded by polarization in a wurtzite crystal structure. Nonpolar and semipolar III-nitrides have been extensively studied since the early 2000s as a solution to the polarizationrelated issues. Removal of polarization is expected to improve the radiative efficiency, optical gain, charge transport, and potentially offer solutions to the challenging problems in III-nitride light-emitting diodes (LEDs) known as efficiency droop and the green gap. In addition, use of nonpolar and semipolar orientations is also predicted to offer polarization pinning in some devices due to anisotropic in-plane strain. Despite the many potential advantages over c-plane, nonpolar and semipolar optoelectronic devices have not successfully replaced conventional c-plane devices in the commercial sector. Here, nonpolar and semipolar III-nitrides are reviewed after more than a decade of development. The successes and challenges of nonpolar and semipolar orientations for applications such as LEDs, laser diodes, superluminescent diodes, and vertical-cavity surface emitting lasers are discussed. New potential avenues for nonpolar and semipolar III-nitrides are also highlighted, including visible-light communication and power electronics. The availability of low-cost, high-crystal-quality substrates with nonpolar or semipolar orientation is discussed and alternative approaches for realizing these orientations are presented, including selective-area bottom-up nanostructures.

“…The design and fabrication of lasers should consider the active region design, optimization of the confinement factor, waveguide design, contact formation, and facet optimization. Most published works explored the utilization of asymmetric InGaN/InGaN MQW active regions [68], insertion of InGaN/GaN shallower-QW layers [69], adding a hole blocking layer prior to the first quantum barrier [70], and interface engineering [71] to reduce the threshold current density and increase the slope efficiency. Similar designs may also be implemented in fabricating semipolar InGaN-based LDs.…”

Section: Devices In Laser-based Vlc Systemsmentioning

confidence: 99%

A tutorial on laser-based lighting and visible light communications: device and technology [Invited]

et al. 2019

This tutorial focuses on devices and technologies that are part of laser-based visible light communication (VLC) systems. Laser-based VLC systems have advantages over their light-emitting-diode-based counterparts, including having high transmission speed and long transmission distance. We summarize terminologies related to laser-based solid-state lighting and VLC, and further review the advances in device design and performance. The high-speed modulation characteristics of laser diodes and superluminescent diodes, the on-chip integration of optoelectronic components in the visible color regime, such as the high-speed integrated photodetector, were introduced. The modulation technology for laser-based white light communication systems, and the challenges for future development were then discussed.