Micro-LED as a Promising Candidate for High-Speed Visible Light Communication

Visible Light Communication (VLC) technology is an emerging technology using visible light modulation that, in the modern world, will mainly facilitate high-speed internet connectivity. VLC provides tremendous advantages compared to conventional radio frequency, such as a higher transmission rate, high bandwidth, low-power consumption, no health hazards, less interference, etc., which make it more prominent in recent days. Due to their outstanding features, including low cost, low power consumption, etc., μ-light-emitting diodes (LEDs) have gained considerable attention for VLC implementation, but mostly for the ability to be used for lighting as well as communications. In this review paper, we will focus mainly on recent developments in VLC applications and various factors affecting the modulation bandwidth of VLC devices. Numerous factors, such as quantum confined stark effect (QCSE), carrier lifetime, carrier recombination time, crystal orientation, etc. affect the modulation bandwidth of LEDs, and more information will be discussed in the following sections. This paper will focus on VLC applications based on LEDs but mainly on semipolar μ-LEDs and μ-LED-based arrays with high bandwidths. Another important application of VLC is underwater optical wireless communication (UOWC), which has drawn a huge interest in marine exploration and underwater connectivity, but still faces some challenges because visible light is being used. In addition, this paper will focus on how the current VLC system modulation bandwidth can be enhanced. Many methods have been introduced, such as decreasing the active layer thickness or effective active area or using doping, but the bandwidth is restricted by the recombination time when the system configuration reaches its limit. Therefore, it is important to find alternative ways such as optimizing the system, using the blue filter or using the equalization technology, which will be addressed later. Overall, this review paper provides a brief overview of the VLC-based system performance and some of its potential prospects. Appl. Sci. 2020, 10, 7384; doi:10.3390/app10207384 www.mdpi.com/journal/applsci Appl. Sci. 2020, 10, 7384 2 of 32

[1]  L. F. del Rosal,et al.  Advances and prospects in high-speed information broadcast using phosphorescent white-light LEDs , 2009, 2009 11th International Conference on Transparent Optical Networks.

[2]  Ravi Teja Velpula,et al.  Full-Color InGaN/AlGaN Nanowire Micro Light-Emitting Diodes Grown by Molecular Beam Epitaxy: A Promising Candidate for Next Generation Micro Displays , 2019, Micromachines.

[3]  Yue-Kai Huang,et al.  Efficiency droop behaviors of InGaN∕GaN multiple-quantum-well light-emitting diodes with varying quantum well thickness , 2007 .

[4]  P. Lefebvre,et al.  Recombination dynamics of excitons in III-nitride layers and quantum wells , 1999 .

[5]  Joachim Wagner,et al.  Reduced nonthermal rollover of wide-well GaInN light-emitting diodes , 2009 .

[6]  S. B. Krupanidhi,et al.  Structural and optical properties of nonpolar (11-20) a-plane GaN grown on (1-102) r-plane sapphire substrate by plasma-assisted molecular beam epitaxy , 2011 .

[7]  K. Thonke,et al.  Development of semipolar (11-22) LEDs on GaN templates , 2016, SPIE OPTO.

[8]  H. Kuo,et al.  Inkjet-Printed Quantum Dot Color Conversion Films for High Resolution and Full Color Micro Light-Emitting Diode (μLED) Displays. , 2020, The journal of physical chemistry letters.

[9]  John A. Rogers,et al.  Recent Advances in Flexible Inorganic Light Emitting Diodes: From Materials Design to Integrated Optoelectronic Platforms , 2018, Advanced Optical Materials.

[10]  S. Denbaars,et al.  Explanation of low efficiency droop in semipolar (202¯1¯) InGaN/GaN LEDs through evaluation of carrier recombination coefficients. , 2017, Optics express.

[11]  Meng-Chyi Wu,et al.  High-Speed Light-Emitting Diodes Emitting at 500 nm With 463-MHz Modulation Bandwidth , 2014, IEEE Electron Device Letters.

[12]  J. Piprek.  Efficiency droop in nitride‐based light‐emitting diodes , 2010 .

[13]  Hao-Chung Kuo,et al.  Mini-LED and Micro-LED: Promising Candidates for the Next Generation Display Technology , 2018, Applied Sciences.

[14]  Zhiyou Guo,et al.  Influence of Current Density and Capacitance on the Bandwidth of VLC LED , 2018, IEEE Photonics Technology Letters.

[15]  Faisal Karim Shaikh,et al.  RF Path and Absorption Loss Estimation for Underwater Wireless Sensor Networks in Different Water Environments , 2016, Sensors.

[16]  Sevia Mahdaliza Idrus,et al.  Indoor Data Transmission Over Ubiquitous Infrastructure of Powerline Cables and LED Lighting , 2015 .

[17]  M. Dawson,et al.  Visible-Light Communications Using a CMOS-Controlled Micro-Light- Emitting-Diode Array , 2012, Journal of Lightwave Technology.

[18]  R. Czernecki,et al.  High speed visible light communication using blue GaN laser diodes , 2016, Security + Defence.

[19]  Sira Yongchareon,et al.  Visible Light Communication: A System Perspective—Overview and Challenges , 2019, Sensors.

[20]  Po-Tsung Lee,et al.  Full-color micro-LED display with high color stability using semipolar (20-21) InGaN LEDs and quantum-dot photoresist , 2020 .

[21]  Xiaolin Zhou,et al.  Laser-based white-light source for high-speed underwater wireless optical communication and high-efficiency underwater solid-state lighting. , 2018, Optics express.

[22]  C. Lin,et al.  High-Bandwidth Green Semipolar (20–21) InGaN/GaN Micro Light-Emitting Diodes for Visible Light Communication , 2020 .

[23]  S. Denbaars,et al.  Semipolar $({\hbox{20}}\bar{{\hbox{2}}}\bar{{\hbox{1}}})$ InGaN/GaN Light-Emitting Diodes for High-Efficiency Solid-State Lighting , 2013, Journal of Display Technology.

[24]  Sergio Pinna,et al.  Polarized monolithic white semipolar (20–21) InGaN light-emitting diodes grown on high quality (20–21) GaN/sapphire templates and its application to visible light communication , 2020 .

[25]  Morteza Monavarian,et al.  Impact of crystal orientation on the modulation bandwidth of InGaN/GaN light-emitting diodes , 2018 .

[26]  S. B. Krupanidhi,et al.  Semipolar and nonpolar GaN epi-films grown on m-sapphire by plasma assisted molecular beam epitaxy , 2014 .

[27]  Duc V. Dinh,et al.  High Bandwidth Freestanding Semipolar (11–22) InGaN/GaN Light-Emitting Diodes , 2016, IEEE Photonics Journal.

[28]  Chi-Wai Chow,et al.  Improved modulation speed of LED visible light communication system integrated to main electricity network , 2011 .

[29]  Fengzhong Qu,et al.  OFDM-based broadband underwater wireless optical communication system using a compact blue LED , 2016 .

[30]  Meng-Chyi Wu,et al.  High-Speed GaN-Based Blue Light-Emitting Diodes With Gallium-Doped ZnO Current Spreading Layer , 2013, IEEE Electron Device Letters.

[31]  P. Heremans,et al.  Large-signal-modulation of high-efficiency light-emitting diodes for optical communication , 2000, IEEE Journal of Quantum Electronics.

[32]  Jianjun Yu,et al.  Demonstration of 575-Mb/s downlink and 225-Mb/s uplink bi-directional SCM-WDM visible light communication using RGB LED and phosphor-based LED. , 2013, Optics express.

[33]  S. Nakamura,et al.  Strain-induced polarization in wurtzite III-nitride semipolar layers , 2006 .

[34]  C. Pontbriand,et al.  An integrated, underwater optical /acoustic communications system , 2010, OCEANS'10 IEEE SYDNEY.

[35]  Lixia Zhao,et al.  Enhancing the spontaneous emission rate by modulating carrier distribution in GaN-based surface plasmon light-emitting diodes. , 2017, Optics express.

[36]  Harald Haas,et al.  High-Speed Visible Light Communication Based on a III-Nitride Series-Biased Micro-LED Array , 2019, Journal of Lightwave Technology.

[37]  Erdan Gu,et al.  Size-dependent light output, spectral shift, and self-heating of 400 nm InGaN light-emitting diodes , 2010 .

[38]  Lai Wang,et al.  2  Gbps/3  m air-underwater optical wireless communication based on a single-layer quantum dot blue micro-LED. , 2020, Optics letters.

[39]  Brian Corbett,et al.  Polarization matching design of InGaN-based semi-polar quantum wells—A case study of (112¯2) orientation , 2014 .

[40]  D. V. Dinh,et al.  Size-Dependent Bandwidth of Semipolar ( $11\overline {2}2$ ) Light-Emitting-Diodes , 2018, IEEE Photonics Technology Letters.

[41]  R. Dupuis,et al.  Control of quantum-confined Stark effect in InGaN∕GaN multiple quantum well active region by p-type layer for III-nitride-based visible light emitting diodes , 2008 .

[42]  Harald Haas,et al.  A review of gallium nitride LEDs for multi-gigabit-per-second visible light data communications , 2017 .

[43]  Mostafa Zaman Chowdhury,et al.  A New Vehicle Localization Scheme Based on Combined Optical Camera Communication and Photogrammetry , 2018, Mob. Inf. Syst..

[44]  Gong-Ru Lin,et al.  High-Speed GaN-Based Green Light-Emitting Diodes With Partially n-Doped Active Layers and Current-Confined Apertures , 2008, IEEE Electron Device Letters.

[45]  D. V. Dinh,et al.  GHz bandwidth semipolar (112¯2) InGaN/GaN light-emitting diodes. , 2016, Optics letters.

[46]  K. Sindhubala,et al.  DESIGN AND IMPLEMENTATION OF VISIBLE LIGHT COMMUNICATION SYSTEM IN INDOOR ENVIRONMENT , 2015 .

[47]  B. Corbett,et al.  Size-Dependent Bandwidth of Semipolar (1122) Light-Emitting-Diodes , 2020 .

[48]  Hao-Chung Kuo,et al.  Optical cross-talk reduction in a quantum-dot-based full-color micro-light-emitting-diode display by a lithographic-fabricated photoresist mold , 2017 .

[49]  Liang Wu,et al.  Visible Light Communication System Design and Link Budget Analysis , 2015, Journal of Lightwave Technology.

[50]  M. S. Islim,et al.  Towards 10 Gb/s orthogonal frequency division multiplexing-based visible light communication using a GaN violet micro-LED , 2017 .

[51]  Xiaolin Zhou,et al.  High-speed underwater optical wireless communication using a blue GaN-based micro-LED. , 2017, Optics express.

[52]  Muataz H. Salih,et al.  A review of visible light communication (VLC) technology , 2020 .

[53]  Chi-Wai Chow,et al.  Using adaptive equalization and polarization-multiplexing technology for gigabit-per-second phosphor-LED wireless visible light communication , 2018, Optics & Laser Technology.

[54]  John A Rogers,et al.  Unusual strategies for using indium gallium nitride grown on silicon (111) for solid-state lighting , 2011, Proceedings of the National Academy of Sciences.

[55]  Liang Wu,et al.  Design and Characterization of Active Matrix LED Microdisplays With Embedded Visible Light Communication Transmitter , 2016, Journal of Lightwave Technology.

[56]  B. Guizal,et al.  Excitonic recombination dynamics in non-polar GaN/AlGaN quantum wells , 2014 .

[57]  Erdan Gu,et al.  Colloidal quantum dot nanocomposites for visible wavelength conversion of modulated optical signals , 2012 .

[58]  Tao Wang,et al.  Stokes shift in semi-polar ( 112¯2) InGaN/GaN multiple quantum wells , 2016 .

[59]  Jinn-Kong Sheu,et al.  III-Nitride-Based Cyan Light-Emitting Diodes With GHz Bandwidth for High-Speed Visible Light Communication , 2016, IEEE Electron Device Letters.

[60]  A. David,et al.  Droop in InGaN light-emitting diodes: A differential carrier lifetime analysis , 2010 .

[61]  Shuji Nakamura,et al.  High-brightness semipolar (2021¯) blue InGaN/GaN superluminescent diodes for droop-free solid-state lighting and visible-light communications. , 2016, Optics letters.

[62]  D. Feezell,et al.  High-Speed Nonpolar InGaN/GaN LEDs for Visible-Light Communication , 2017 .

[63]  Qingquan Liu,et al.  High-Speed Visible Light Communications: Enabling Technologies and State of the Art , 2018 .

[64]  Hao-Chung Kuo,et al.  High-Performance InGaN-Based Green Resonant-Cavity Light-Emitting Diodes for Plastic Optical Fiber Applications , 2009, Journal of Lightwave Technology.

[65]  Chi-Wai Chow,et al.  Real-time white-light phosphor-LED visible light communication (VLC) with compact size. , 2013, Optics express.

[66]  Hongxing Jiang,et al.  III-nitride micro-emitter arrays: development and applications , 2008 .

[67]  I. White,et al.  High Bandwidth GaN-Based Micro-LEDs for Multi-Gb/s Visible Light Communications , 2016, IEEE Photonics Technology Letters.

[68]  Joseph M. Kahn,et al.  Sensitivity Improvement in 100 Gb/s-per-Wavelength Links Using Semiconductor Optical Amplifiers or Avalanche Photodiodes , 2016, Journal of Lightwave Technology.

[69]  J. Bowers,et al.  GaN-Based Miniaturized Cyan Light-Emitting Diodes on a Patterned Sapphire Substrate With Improved Fiber Coupling for Very High-Speed Plastic Optical Fiber Communication , 2012, IEEE Photonics Journal.

[70]  B. Guizal,et al.  Recombination dynamics of excitons with low non-radiative component in semi-polar (10-11)-oriented GaN/AlGaN multiple quantum wells , 2014 .

[71]  S. Denbaars,et al.  Internal quantum efficiency and carrier dynamics in semipolar (2021) InGaN/GaN light-emitting diodes. , 2017, Optics express.

[72]  Y. Arakawa,et al.  Direct study of nonlinear carrier recombination in InGaN quantum well structures , 2011 .

[73]  E. Schubert,et al.  Efficiency droop in light‐emitting diodes: Challenges and countermeasures , 2013 .

[74]  Shlomi Arnon.  Optimised optical wireless car-to-traffic-light communication , 2014, Trans. Emerg. Telecommun. Technol..

[75]  R. Horng,et al.  Improved Optoelectronic Performance of High-Voltage Ultraviolet Light-Emitting Diodes Through Electrode Designs , 2017, IEEE Transactions on Electron Devices.

[76]  H. Haas,et al.  On-chip GaN-based dual-color micro-LED arrays and their application in visible light communication. , 2019, Optics express.

[77]  E. Purcell.  Spontaneous Emission Probabilities at Radio Frequencies , 1995 .

[78]  Shinya Saito,et al.  Research and Development on Underwater Visible Light Communication Systems , 2015 .

[79]  Latif Ullah Khan,et al.  Visible light communication: Applications, architecture, standardization and research challenges , 2017, Digit. Commun. Networks.

[80]  Carrick Detweiler,et al.  AquaOptical: A lightweight device for high-rate long-range underwater point-to-point communication , 2009, OCEANS 2009.

[81]  Yuhan Dong,et al.  A Survey of Underwater Optical Wireless Communications , 2017, IEEE Communications Surveys & Tutorials.

[82]  Lixia Zhao,et al.  Influence of quantum confined Stark effect and carrier localization effect on modulation bandwidth for GaN-based LEDs , 2017 .

[83]  Richard A. Soref,et al.  Practical enhancement of photoluminescence by metal nanoparticles , 2009 .

[84]  Erdan Gu,et al.  GaN micro-light-emitting diode arrays with monolithically integrated sapphire microlenses , 2004 .

[85]  Erdan Gu,et al.  CMOS-Controlled Color-Tunable Smart Display , 2012, IEEE Photonics Journal.

[86]  Rajendran Parthiban,et al.  LED Based Indoor Visible Light Communications: State of the Art , 2015, IEEE Communications Surveys & Tutorials.

[87]  D. H. Mash,et al.  Light-emitting diodes , 1977, Nature.

[88]  Xuan Tang,et al.  Car-to-Car Visible Light Communications , 2017 .

[89]  Takashi Mukai,et al.  Surface plasmon enhanced spontaneous emission rate of InGaN∕GaN quantum wells probed by time-resolved photoluminescence spectroscopy , 2005 .

[90]  Wei Chen,et al.  Improving the modulation bandwidth of LED by CdSe/ZnS quantum dots for visible light communication. , 2016, Optics express.

[91]  James S. Speck,et al.  The efficiency challenge of nitride light‐emitting diodes for lighting , 2015 .

[92]  O. Trescases,et al.  A dimmable LED driver for visible light communication (VLC) based on LLC resonant DC-DC converter operating in burst mode , 2013, 2013 Twenty-Eighth Annual IEEE Applied Power Electronics Conference and Exposition (APEC).

[93]  R. Dupuis,et al.  Control of Quantum-Confined Stark Effect in InGaN-Based Quantum Wells , 2009, IEEE Journal of Selected Topics in Quantum Electronics.

[94]  Takashi Mukai,et al.  Surface-plasmon-enhanced light emitters based on InGaN quantum wells , 2004, Nature materials.

[95]  Gang Wang,et al.  Contrary luminescence behaviors of InGaN/GaN light emitting diodes caused by carrier tunneling leakage , 2011 .

[96]  Jun-Xi Wang,et al.  Enhancement of the modulation bandwidth for GaN-based light-emitting diode by surface plasmons. , 2015, Optics express.

[97]  M. Shur,et al.  Well-width-dependent carrier lifetime in AlGaN∕AlGaN quantum wells , 2007 .