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

Monavarian, Morteza; Rashidi, Arman; Feezell, Daniel

doi:10.1002/pssa.201800628

Cited by 66 publications

(82 citation statements)

References 271 publications

(367 reference statements)

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“…Due to the presence of the large electrical polarization fields in c-plane group-III nitrides, strong QCSE is present in quantum well LEDs based on c-plane group-III nitrides. Making devices on nonpolar/semipolar planes promises the reduced electrical polarization fields and thus the improved device performance [39,[100][101][102][103]. Nonetheless, having high quality epitaxy-ready nonpolar/semipolar substrates/templates has remained challenging [39].…”

Section: Nonpolar Algan Nanowire Uv Ledsmentioning

confidence: 99%

“…Making devices on nonpolar/semipolar planes promises the reduced electrical polarization fields and thus the improved device performance [39,[100][101][102][103]. Nonetheless, having high quality epitaxy-ready nonpolar/semipolar substrates/templates has remained challenging [39]. This makes using nanowire structures appealing: For group-III nitride nanowires grown either by MOCVD or MBE, the sidewalls are naturally nonpolar, due to the wurtzite structure.…”

Section: Nonpolar Algan Nanowire Uv Ledsmentioning

confidence: 99%

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AlGaN Nanowires for Ultraviolet Light-Emitting: Recent Progress, Challenges, and Prospects

Zhao

et al. 2020

Micromachines

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In this paper, we discuss the recent progress made in aluminum gallium nitride (AlGaN) nanowire ultraviolet (UV) light-emitting diodes (LEDs). The AlGaN nanowires used for such LED devices are mainly grown by molecular beam epitaxy (MBE) and metalorganic chemical vapor deposition (MOCVD); and various foreign substrates/templates have been investigated. Devices on Si so far exhibit the best performance, whereas devices on metal and graphene have also been investigated to mitigate various limitations of Si substrate, e.g., the UV light absorption. Moreover, patterned growth techniques have also been developed to grow AlGaN nanowire UV LED structures, in order to address issues with the spontaneously formed nanowires. Furthermore, to reduce the quantum confined Stark effect (QCSE), nonpolar AlGaN nanowire UV LEDs exploiting the nonpolar nanowire sidewalls have been demonstrated. With these recent developments, the prospects, together with the general challenges of AlGaN nanowire UV LEDs, are discussed in the end.

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Section: Nonpolar Algan Nanowire Uv Ledsmentioning

confidence: 99%

Section: Nonpolar Algan Nanowire Uv Ledsmentioning

confidence: 99%

AlGaN Nanowires for Ultraviolet Light-Emitting: Recent Progress, Challenges, and Prospects

Zhao

et al. 2020

Micromachines

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“…Furthermore, we note that if carrier localization effects were the origin of the green gap problem, nonpolar In-GaN/GaN QW systems should not exhibit this efficiency reduction for the following reasons. 73,74 With the macroscopic built-in field absent in these structures, the attractive Coulomb interaction between electrons and holes leads to exciton localization effects observed both in theory and experiment. 31,41,75,76 In a Hartree-type picture the in-plane separation between electrons and holes will be strongly reduced due to their attractive Coulomb interaction.…”

Section: Electron-hole Wave Function Overlapmentioning

confidence: 99%

Polar ( In , Ga ) N /
Tanner
¹
,
Dawson
²
,
Kappers
³

et al. 2020
Phys. Rev. Applied

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We present a detailed theoretical analysis of the electronic and optical properties of c-plane In-GaN/GaN quantum well structures with In contents ranging from 5% to 25%. Special attention is paid to the relevance of alloy induced carrier localization effects to the green gap problem. Studying the localization length and electron-hole overlaps at low and elevated temperatures, we find alloyinduced localization effects are crucial for the accurate description of InGaN quantum wells across the range of In content studied. However, our calculations show very little change in the localization effects when moving from the blue to the green spectral regime; i.e. when the internal quantum efficiency and wall plug efficiencies reduce sharply, for instance, the in-plane carrier separation due to alloy induced localization effects change weakly. We conclude that other effects, such as increased defect densities, are more likely to be the main reason for the green gap problem. This conclusion is further supported by our finding that the electron localization length is large, when compared to that of the holes, and changes little in the In composition range of interest for the green gap problem. Thus electrons may become increasingly susceptible to an increased (point) defect density in green emitters and as a consequence the nonradiative recombination rate may increase.

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“…30 Figure 1. 18. SEM images showing (a) processing issues during flip-chip using PEC etching resulting in poor device yield, and (b) non-uniform morphology evolution during ELO regrowth with various V/III ratio and temperature combinations [107,108].…”

Section: List Of Figuresmentioning

confidence: 99%

“…Schematics of selected crystal planes in a wurtzite GaN lattice characterized by different inclination angles (θ). Reprinted from[18], with permission from John Wiley and Sons. 17…”

mentioning

confidence: 99%

Nonpolar GaN-based VCSELs with lattice-matched nanoporous distributed Bragg reflector mirrors

Mishkat-Ul-Masabih

Aragon

Monavarian

et al. 2020

Gallium Nitride Materials and Devices XV

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I am grateful to many people for making this work possible. First and foremost, I would like to thank my advisor Prof. Daniel Feezell for his dedicated guidance and support. Early on in my degree, I remember him mentioning that VCSEL projects are always of high risk and high reward. For the longest time, I doubted myself on whether I would be able to fulfill all the project requirements. But, Prof. Feezell believed in my ability and urged me to push forward which ultimately lead to groundbreaking results from my VCSEL project. Not only did I learn a ton from his vast knowledge on IIInitride materials and devices, his constructive criticisms greatly improved the quality of my work and allowed me to grow as a researcher. Next, I am thankful to my committee members and collaborators, Prof. Ganesh Balakrishnan, Prof. Sang Han, and Dr. Ting Luk for their time and suggestions. Their valuable insight on optical, electrical, and mechanical properties of semiconductors helped me tremendously in understanding the material characteristics and device performance of my VCSELs. I cannot express the immense gratitude I feel for my fellow group members, both past and present. All of whom have helped me towards the completion of my PhD in some way or another. Many thanks to Ashwin, Morteza, Mohsen, and Mike for introducing me to MOCVD and for taking care of my growths when I was busy doing something else. Discussions regarding fabrication with Andrew, Mahmoud, Rhett, Kenny, Farnood, and Abdel have always helped me in developing processes very v quickly and reliably. I am also grateful to Serdal, Arman, and Isaac for assisting me in various material and device related characterizations. Many of the accomplishments mentioned in this thesis could not have been possible without the support of the technical and/or administrative staff. As such, I am forever indebted to the ECE, CHTM, and CINT staff members for putting up with my numerous requests and questions throughout the years. Beyond the appreciation of the technical side of things, I would like to thank all my friends from back home and the ones I made during the course of my study. They were always there to lend a helping hand or to simply distract me from work whenever graduate student life became too overwhelming. Furthermore, I must also acknowledge the Bangladeshi community here at UNM for making Albuquerque feel like home, even though my real home is halfway around the world. Looking back, I will forever cherish these memories. Last, but certainly not least, I would like to thank my parents, my older sister, and my younger brother. I would not be where I am at today without their unconditional love and encouragement. They have sacrificed a lot so that I can pursue a career of my choice, even if it meant me being away from home for an extended period time. I only hope that the work I performed in this thesis is substantial enough to repay them and make them proud. vi

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

Cited by 66 publications

References 271 publications

AlGaN Nanowires for Ultraviolet Light-Emitting: Recent Progress, Challenges, and Prospects

AlGaN Nanowires for Ultraviolet Light-Emitting: Recent Progress, Challenges, and Prospects

Polar ( In , Ga ) N /
Tanner
¹
,
Dawson
²
,
Kappers
³

et al. 2020
Phys. Rev. Applied

Nonpolar GaN-based VCSELs with lattice-matched nanoporous distributed Bragg reflector mirrors

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

Cited by 66 publications

References 271 publications

AlGaN Nanowires for Ultraviolet Light-Emitting: Recent Progress, Challenges, and Prospects

AlGaN Nanowires for Ultraviolet Light-Emitting: Recent Progress, Challenges, and Prospects

Polar ( In , Ga ) N / Tanner1, Dawson2, Kappers3 et al. 2020Phys. Rev. Applied

Nonpolar GaN-based VCSELs with lattice-matched nanoporous distributed Bragg reflector mirrors

Contact Info

Product

Resources

About

Polar ( In , Ga ) N /
Tanner
¹
,
Dawson
²
,
Kappers
³

et al. 2020
Phys. Rev. Applied