Publications

Book Chapters

    1. H. Fu and Y. Zhao, “Efficiency droop in InGaN/GaN LEDs”, chapter in “Nitride Semiconductor Light-Emitting Diodes”, 2nd edition, Elsevier, (2017).
    2. Y. R. Wu, C. Y. Huang, Y. Zhao, and J. S. Speck, “Nonpolar and Semipolar LEDs”, chapter in “Nitride Semiconductor Light-Emitting Diodes (LEDs): Materials, Technologies and Applications”, edited by Prof. J. J. Huang, Prof. H. C. Kuo, and Prof. S. C. Shen, Woodhead Publishing, (2014).

Journals

      1. Z. Lu, et al., “Experimental demonstration of non-line-of-sight visible light communication using a GaN-based micro-LED and practical IEEE 802.11ac”, submitted.
      2. H. Fu, X. Huang, H. Chen, Z. Lu, I. Baranowski, and Y. Zhao, “Ultra-low turn-on voltage and on-resistance vertical GaN-on-GaN Schottky power diodes with high mobility double drift layers”, submitted.
      3. H. Fu, X. Huang, H. Chen, Z. Lu, and Y. Zhao, “Fabrication and characterization of ultra-wide bandgap AlN based Schottky diodes on sapphire by MOCVD”, accepted to IEEE Journal of the Electron Devices Society
      4. Z. Lu, P. Tian, H. Chen, I. Baranowski, H. Fu, X. Huang, J. Montes, Y. Fan, H. Wang, X. Liu, R. Liu, and Y. Zhao, “Active tracking system for visible light communication using a GaN-based micro-LED and NRZ-OOK“, Opt. Express, vol. 25, 17971 (2017).
      5. H. Fu, X. Zhang, X. Huang, I. Baranowski, H. Chen, Z. Lu, J. Montes, and Y. Zhao, “Demonstration of  AlN Schottky barrier diodes with blocking voltage over 1kV“, IEEE Electron Device Lett., vol. 38, 1286 (2017).  Highlight in Silicon Valley Microelectronics, Semiconductor Today, etc.
      6. H. Chen, X. Huang, H. Fu, Z. Lu, X. Zhang, J. A. Montes, and Y. Zhao “Characterizations of nonlinear optical properties on GaN crystals in polar, nonpolar, and semipolar orientations“, Appl. Phys. Lett., vol. 110, 181110 (2017). 
      7. H. Fu, X. Huang, H. Chen, Z. Lu, X. Zhang, and Y. Zhao, “Effect of buffer layer design on vertical GaN-on-GaN p-n and Schottky power diodes“,  IEEE Electron Device Lett., vol. 38, 763 (2017).  Highlight in Semiconductor Today.
      8. X. Huang, H. Fu, H. Chen, X. Zhang, Z. Lu, J. Montes, M. Iza, S. P. DenBaars, S. Nakamura, and Y. Zhao,  “Nonpolar and semipolar InGaN/GaN multiple-quantum-well solar cells with improved carrier collection efficiency“, Appl. Phys. Lett., vol. 110, 161105 (2017). Highlight in Semiconductor Today.
      9. H. Chen, H. Fu, X. Huang, Z. Lu, X. Zhang, J. Montes, and Y. Zhao, “Optical cavity effects in InGaN core-shell light-emitting diodes with metallic coating“, IEEE Photonics J., vol. 9, 8200828 (2017).
      10. H. Fu, H. Chen, X. Huang, Z. Lu,  and  Y. Zhao, “Theoretical analysis of modulation doping effects on intersubband transition properties of semipolar AlGaN/GaN quantum well“, J. Appl. Phys., vol. 121, 014501 (2017).
      11. H. Fu, Z. Lu,  and  Y. Zhao,  “Analysis of low efficiency droop of semipolar InGaN quantum well light-emitting diodes by modified rate equation with weak phase-space filling effect“, AIP Adv., vol. 6, 065013 (2016).
      12. X. Huang, H. Fu, H. Chen, Z. Lu, D. Ding, and  Y. Zhao,  “Analysis of loss mechanisms in InGaN solar cells using a semi-analytical model“, J. Appl. Phys., vol. 119, 213101 (2016).
      13. H. Fu, Z. Lu, X. Huang, H. Chen, and  Y. Zhao,  “Crystal orientation dependent Intersubband transition in semipolar AlGaN/GaN single quantum well for optoelectronic applications“, J. Appl. Phys., vol. 119, 174502 (2016).
      14. H. Chen, H. Fu, Z. Lu, X. Huang, and  Y. Zhao,  “Optical properties of highly polarized InGaN light-emitting diodes modified by plasmonic metallic grating“, Opt. Express, vol. 24, A856 (2016).
      15. H. Fu, Z. Lu, X. Zhao, Y. H. Zhang, S. P. DenBaars, S. Nakamura, and  Y. Zhao,  “Study of low efficiency droop in semipolar (20-2-1) InGaN light-emitting diodes by time-resolved photoluminescence“, J. Display Technol., vol. 12, 736 (2016).
      16. R.Ivanov, S. Marcinkevicius, Y. Zhao, D. L. Becerra, S. Nakamura, S. P. DenBaars, and J. S. Speck,  “Impact of carrier localization on radiative recombination times in semipolar (20-21) InGaN/GaN quantum wells“, Appl. Phys. Lett., vol. 107, 211109 (2015).
      17. J. Xue, Y. Zhao, S. H. Oh, J. S. Speck, S. P. DenBaars, S. Nakamura, and R. J. Ram, “Thermally enhanced blue light-emitting diodes“, Appl. Phys. Lett., vol. 107, 121109 (2015). Highlight in Nature Photonics.
      18. C. C. Pan, Q. Yan, H. Fu, Y. Zhao, Y. R. Wu, C. G. Van de Walle, S. Nakamura, and S. P. DenBaars, “High optical power and low efficiency droop blue light-emitting diodes using compositionally step-graded InGaN barrier“, Electron. Lett., vol. 51, pp. 1187 – 1189 (2015). 
      19. K. Gelzinyte, S Marcinkevicius, Y. Zhao, D. L. Becerra, S. Nakamura, S. P. DenBaars, and J. S. Speck,  “High spatial uniformity of photoluminescence spectra in semipolar (20-21) plane InGaN/GaN quantum wells“, J. Appl. Phys., vol. 117, 023111 (2015). 
      20. D. L. Becerra, Y. Zhao, S. H. Oh, C. D. Pynn, K. Fujito, S. P. DenBaars, and S. Nakamura, “High-power low-droop violet semipolar (30-3-1) InGaN/GaN light-emitting diodes with thick active layer design“,  Appl. Phys. Lett., vol. 105, 171106 (2014). Highlight in Semiconductor Today.
      21. Y. Zhao, R. M. Farrell, Y. R. Wu, and J. S. Speck, “Valence band states and polarized optical emission from nonpolar and semipolar III–nitride quantum well optoelectronic devices”,  Jpn. J. Appl. Phys. Selected Topics in Applied Physics, vol. 53, 100206 (2014). Invited paper.
      22. S. Marcinkevicius, K. Gelzinyte, Y. Zhao, S. Nakamura, S. P. DenBaars, and J. S. Speck, “Carrier distributation between different potential cites in semipolar quantum well studied by near-field photoluminescence“, Appl. Phys. Lett., vol. 105, 111108 (2014). 
      23. F. Wu, Y. Zhao, A. Romanov, S. P. DenBaars, S. Nakamura, and J. S. Speck, “Stacking faults and interface roughening in semipolar (20-2-1) single InGaN quantum wells for long wavelength emission”, Appl. Phys. Lett., vol. 104, 151901 (2014). 
      24. Y. Ji, W. Liu, T. Erdem, R. Chen, S. T. Tan, Z. H. Zhang, Z. Ju, X. Zhang, H. Sun, X. W. Sun, Y. Zhao, S. P. DenBaars, S. Nakamura, and H. V. Demir, “Comparative study of field-dependent carrier dynamics and emission kinetics of InGaN/GaN light-emitting diodes grown on (11-22) semipolar versus (0001) polar planes”, Appl. Phys. Lett., vol. 104, 143506 (2014). 
      25. S. Marcinkevicius, R. Ivanov, Y. Zhao, S. Nakamura, S. P. DenBaars, and J. S. Speck, “Highly polarized photoluminescence and its dynamics in semipolar (20-2-1) InGaN/GaN quantum well”, Appl. Phys. Lett., vol. 104, 111113 (2014). 
      26. Y. Zhao, F. Wu, T. J. Yang, Y. R. Wu, S. Nakamura, and J. S. Speck, “Atomic scale nanofacet structure in semipolar InGaN single quantum well”, Appl. Physics Express, vol. 7, 025503 (2014). 
      27. M. T. Hardy, F. Wu, C. Y. Huang, Y. Zhao, D. Feezell, J. S. Speck, S. Nakamura, and S. P. DenBaars, “Impact of p-GaN temperature and AlGaN barrier composition on (20-21) green laser diodes”, IEEE Photonics Technol. Lett., vol. 26, 43 (2014). 
      28. S. Marcinkevicius, Y. Zhao, K. M. Kelchner, S. Nakamura, S. P. DenBaars, and J. S. Speck, “Near-field investigation of spatial variations of (20-2-1) InGaN quantum well emission spectra”, Appl. Phys. Lett., vol. 102, 131116 (2013). 
      29. Y. Zhao, S. H. Oh, F. Wu, Y. Kawaguchi, S. Tanaka, K. Fujito, J. S. Speck, S. P. DenBaars, and S. Nakamura, “Green semipolar (20-2-1) InGaN light-emitting diodes with small wavelength shift and narrow spectral width”, Appl. Phys. Express, vol. 6, 062102 (2013). Highlight in Nature Photonics, vol. 7 585 (2013), Compound Semiconductor, etc & “Research Highlights” on front page of APEX & Top 20 most downloaded articles May to July 2013 in APEX.
      30. Y. Kawaguchi, S. C. Huang, R. M. Farrell, Y. Zhao, J .S. Speck, S. P. DenBaars, and S. Nakamura, “Dependence of electron overflow on emission wavelength and crystallographic orientation in single-quantum-well III-nitride light-emitting diodes”, Appl. Phys. Express, vol. 6, 052103 (2013). “Research Spotlights” & Top 20 most downloaded articles April and June 2013 in APEX.
      31. Y. Zhao, F. Wu, C. Y. Huang, Y. Kawaguchi, S. Tanaka, K. Fujito, J. S. Speck, S. P. DenBaars, and S. Nakamura, “Suppressing the void defects in the long wavelength semipolar InGaN quantum wells by growth rate optimization”, Appl. Phys. Lett., vol. 102, 091905 (2013). 
      32. S. P. DenBaars, D. Feezell, K. Kelchner, S. Pimputkar, C. C. Pan, C. C. Yen, S. Tanaka, Y. Zhao, N. Pfaff, R. Farrell, M. Iza, S. Keller, U. Mishra, J. S. Speck, and S. Nakamura, “Development of gallium-nitride-based light-emitting diodes (LEDs) and laser diodes for energy efficient lighting and displays”, Acta Mater., vol. 61, 945 (2013). (Invited) 
      33. Y. Zhao, Q. Yan, D. Feezell, K. Fujito, C. G. Van de Walle, J. S. Speck, S. P. DenBaars, and S. Nakamura, “Optical polarization characteristics of semipolar (30-31) and (30-3-1) InGaN/GaN light-emitting diodes”, Opt. Express, vol. 21, A53 (2013).
      34. Y. Kawaguchi, C. Y. Huang, Y. R. Wu, Y. Zhao, S. P. DenBaars, and S. Nakamura, “Semipolar 20-21 single-quantum-well red light-emitting diodes with a low forward voltage”, Jpn. J. Appl. Phys., vol. 52, 08JC08 (2013). 
      35. C. C. Pan, T. Gilberto, N. Pfaff, S. Tanaka, Y. Zhao, D. Feezell, J. S. Speck, S. Nakamura, and S. P. DenBaars, “Reduction in thermal droop using thick quantum well structure in semipolar (20-2-1) blue light-emitting diodes”, Appl. Phys. Express, vol. 5, 102103 (2012). 
      36. Y. Kawaguchi, C. Y. Huang, Y. R. Wu, Q. Yen, C. C. Pan, Y. Zhao, S. Tanaka, K. Fujito, D. Feezell, C. G. Van de Walle, S. P. DenBaars, and S. Nakamura, “Influence of polarity on carrier transport in semipolar (20-2-1) and (20-21) multiple-quantum-well light-emitting diodes”, Appl. Phys. Lett., vol. 100, 231110 (2012). “APL Editor’s Picks of the Year Award” in 2012 &“Research Highlights” of AIP June 2012 & “Editor’s Choice” in the AIP Virtual Journal of Nanoscience and Technology, Vol. 25(25), June 2012 & Top 20 most downloaded articles June 2012 in APL.
      37. C. C. Pan, S. Tanaka, F. Wu, Y. Zhao, J. S. Speck, S. Nakamura, S. P. DenBaars, and D. Feezell, “High-power, low-efficiency-droop (20-2-1) single-quantum-well blue light-emitting diodes”, Appl. Phys. Express, vol. 5, 062103 (2012). Top 20 most downloaded articles June and July 2012 in APEX. “Research Highlights” on front page of APEX & Top 20 most downloaded articles September and October 2012 in APEX.
      38. Y. Zhao, Q. Yan, C. Y. Huang, S. C. Huang, P. S. Hsu, S. Tanaka, C. C. Pan, Y. Kawaguchi, K. Fujito, D. Feezell, C. G. Van de Walle, J. S. Speck, S. P. DenBaars, and S. Nakamura, “Indium incorporation and emission properties of nonpolar and semipolar InGaN quantum wells”, Appl. Phys. Lett., vol. 100, 201108 (2012). 
      39. J. J. Richardson, I. Koslow, C. C. Pan, Y. Zhao, J. S. Ha, and S. DenBaars, “Semipolar single-crystal ZnO films deposited by low-temperature aqueous solution phase epitaxy on GaN light-emitting diodes”, Appl. Phys. Express, vol. 4, 126502 (2011). Top 20 most downloaded articles December 2011 in APEX.
      40. C. Y. Huang, Q. Yan, Y. Zhao, D. Feezell, K. Fujito, C. G. Van de Walle, J. S. Speck, S. P. DenBaars, and S. Nakamura, “Influence of Mg-doped barriers on semipolar multi-quantum-well light-emitting diodes”, Appl. Phys. Lett., vol. 99, 141114 (2011). 
      41. Y. Zhao, S. Tanaka, Q. Yan, C. Y. Huang, R. B. Chung, C. C. Pan, K. Fujito, D. Feezell, C. G. Van de Walle, J. S. Speck, S. P. DenBaars, and S. Nakamura, “High optical polarization ratio from semipolar (20-2-1) blue-green InGaN/GaN light-emitting diodes”, Appl. Phys. Lett., vol. 99, 051109 (2011). 
      42. Y. Zhao, S. Tanaka, C. C. Pan, K. Fujito, D. Feezell, J. S. Speck, S. P. DenBaars, and S. Nakamura, “High-power blue-violet semipolar (20-2-1) InGaN/GaN light-emitting diodes with low efficiency droop at 200 A/cm2”, Appl. Phys. Express, vol. 4, 082104 (2011). Highlight in Science, Optical Society of America, Semiconductor Today, etc. “Most Cited APEX Articles of the Year Award” in 2012 & Top 20 most downloaded articles July 2011 in APEX.
      43. S. Tanaka, Y. Zhao, I. Koslow, C. C. Pan, H. T. Chen, J. Sonoda, S. P. DenBaars, and S. Nakamura, “Droop improvement in high current range on PSS-LEDs”, Electron. Lett., vol. 47, pp. 335 – 336 (2011). 
      44. S. Yamamoto, Y. Zhao, C. C. Pan, R. B. Chung, K. Fujito, J. Sonoda, S. P. DenBaars, and S. Nakamura, “High-efficiency single-quantum-well green and yellow-green light-emitting diodes on semipolar (20-21) GaN substrates”, Appl. Phys. Express,vol. 3, 122102 (2010). Top 20 most downloaded articles November and December 2010 in APEX.
      45. Y. Zhao, J. Sonoda, C. C. Pan, S. Brinkley, I. Koslow, H. Ohta, S. P. DenBaars, and S. Nakamura, “30-mW-class high-power and high-efficiency blue semipolar (10-1-1) InGaN/GaN light-emitting diodes obtained by backside roughening technique”, Appl. Phys. Express, vol. 3, 102101 (2010). Highlight in Laser Focus World, Photonics, etc & Top 20 most downloaded articles September and October 2010 in APEX.
      46. Y. Zhao, J. Sonada, I. Koslow, C. C. Pan, H. Ohta, J. S. Ha, S. P. DenBaars, and S. Nakamura, “Optimization of device structure for bright blue semipolar (10-1-1) light emitting diodes via metalorganic chemical vapor deposition”, Jpn. J. Appl. Phys., vol. 49, 070206 (2010). Highlight in Semiconductor Today, etc. Top 20 most downloaded articles July and August 2010 in JJAP.

Conferences (Refereed)

      1. Chen, X. Huang, H. Fu, Z. Lu, J. Montes, and Y. Zhao, “Characterizations of Kerr refractive index and nonlinear absorption on GaN crystals in polar, nonpolar and semipolar orientations”, The 59th Electronic Materials Conference (EMC 2017), Jun 2017, South Bend, IN, Oral Presentation.
      2. Huang, H. Fu, H. Chen, Z. Lu, J. Montes, M. Iza, S. P. DenBaars, S. Nakamura, and Y. Zhao, “Outstanding high temperature performance of nonpolar and semipolar InGaN solar cells”, The 59th Electronic Materials Conference (EMC 2017), Jun 2017, South Bend, IN, Oral Presentation.
      3. X. Huang, H. Fu, H. Chen, Z. Lu, J. Montes, and Y. Zhao, “Highly thermal robust InGaN/GaN multi-quantum well (MQW) solar cells “, The 44th IEEE Photovoltaic Specialists Conference (PVSC 2017), Jun 2017, Washington,DC, Poster Presentation.
      4. H. Fu, X. Huang, H. Chen, Z. Lu, X. Zhang, and  Y. Zhao, “Analysis of reversed breakdown and leakage mechanisms of AlN Schottky diodes operating at elevated temperature”, 2017 MRS Spring Meeting, Apr 2017, Phoenix, AZ, Oral Presentations.
      5. X. Huang, H. Fu, H. Chen, Z. Lu, X. Zhang, M. Iza, S. DenBaars, S. Nakamura, and  Y. Zhao, “Demonstration of Nonpolar and semipolar InGaN/GaN multi-quantum well (MQW) solar cells”, 2017 MRS Spring Meeting, Apr 2017, Phoenix, AZ, Oral Presentations.
      6. H. Fu, X. Huang, H. Chen, Z. Lu, and Y. Zhao, “On the reverse breakdown and leakage mechanisms of AlN Schottky diodes at high temperature”, 2016 International Workshop on Nitride Semiconductors (IWN 2016), Oct 2016, Orlando, FL, Poster Presentation (Late News).
      7. X. Huang, H. Fu, H. Chen, Z. Lu, D. Ding, and Y. Zhao, “Farbication and characterization of nonpolar and semipolar InGaN/GaN multi-quantum well (MQW) solar cells”, 2016 International Workshop on Nitride Semiconductors (IWN 2016), Oct 2016, Orlando, FL, Oral Presentation (Late News).
      8. X. Huang, H. Fu, H. Chen, Z. Lu, D. Ding, and Y. Zhao, “Theoretical study on efficiency limits and loss analysis for single-junction InGaN solar cells using a semi-analytical model”, 2016 International Workshop on Nitride Semiconductors (IWN 2016), Oct 2016, Orlando, FL, Oral Presentation.
      9. Z. Lu, P. Tian, H. Fu, X. Huang, H. Chen, X. Liu, R. Liu, and Y. Zhao, “The effect of reflection on visible light communication system using a Gallium Nitride uLED and IEEE 802.11ac”, 2016 International Workshop on Nitride Semiconductors (IWN 2016), Oct 2016, Orlando, FL, Poster Presentation.
      10. H. Fu, Z. Lu, X huang, H. Chen, and Y. Zhao, “Crystal orientation dependent intersubband transition in semipolar AlGaN/GaN quantum well for optoelectronic applications”, 2016 International Workshop on Nitride Semiconductors (IWN 2016), Oct 2016, Orlando, FL, Oral Presentation.
      11. H. Chen, H. Fu, X. Huang, Z. Lu, and Y. Zhao, “Polarization-dependent emission properties of InGaN light-emitting diodes modified by metallic grating”, 2016 International Workshop on Nitride Semiconductors (IWN 2016), Oct 2016, Orlando, FL, Poster Presentation.
      12. X. Huang, H. Fu, H. Chen, Z. Lv, D. Ding, and Y. Zhao, “Analysis of loss mechanisms in single-junction InGaN solar cells using a semi-analytical model”, The 58th TMS Electronic Materials Conference (EMC 2016), Jun 2016, Newark, DE, Oral Presentation.
      13. H. Fu, Z. Lu, X. Huang, H. Chen, and Y. Zhao, “Terahertz Intersubband Transition in Semipolar AlGaN/GaN Quantum Wells for Optoelectronic Applications”, The 58th Electronic Materials Conference (EMC 2016), Jun 2016, Newark, DE, Oral Presentation.
      14. H. Chen, H. Fu, Z. Lu, X. Huang, and Y. Zhao, “Optical Properties of Highly Polarized InGaN Light-Emiting Diodes Coated with Silver Grating”, The 58th Electronic Materials Conference (EMC 2016), Jun 2016, Newark, DE, Oral Presentation.
      15. X. Huang, H. Fu, H. Chen, Z. Lv, D. Ding, and Y. Zhao,  “Device Simulation and Loss Analysis for Single-Junction InGaN Solar Cells Using a Semi-Analytical Model” ,The 43rd IEEE Photovoltaic Specialists Conference (PVSC 2016), Jun 2016, Portland, OR, Poster Presentation.
      16. Z. Lu, H. Wang, S. Naqvi, Y. Zhao, H. Song, and J. M. B. Christen, “A Point of Care Electrochemical Impedance Spectroscopy Device”, The 28th IEEE  International System-on-Chip Conference (SOCC 2015), Sep 2015, Beijing, China, Oral Presentation.
      17. H. Fu, Z. Lu, and Y. Zhao, “Weak phase-space willing effect on the modeling of low-droop semipolar InGaN light emitting diodes”, The 11th International Conference on Nitride Semiconductors (ICNS 2015), Aug 2015, Beijing, China, Oral Presentation.
      18. H. Fu, Z. Lu, and Y. Zhao, “The modeling of low-droop semipolar InGaN light emitting diodes with weak phase-space filling effect”, 2015 Compound Semiconductor Week (CSW 2015) and the 42nd International Symposium on Compound Semiconductors (ISCS 2015), Jun 2015, Santa Barbara, CA, Oral Presentation.
      19. Z. Lu, H. Fu, H. Song, and Y. Zhao, “A CMOS sun tracker for an application of CPV”, 2015 Compound Semiconductor Week (CSW 2015) and the 42nd International Symposium on Compound Semiconductors (ISCS 2015), Jun 2015, Santa Barbara, CA, Poster Presentation.
      20. S. Marcinkevicius, K. Gelzinyte, R. Ivanov, Y. Zhao, S. Nakamura, S. P.DenBaars, and J. S. Speck, “Optical Properties of Semipolar (20-21) Plane InGaN Quantum Wells Studied on the Nanoscale”, 2015 Compound Semiconductor Week (CSW 2015) and the 42nd International Symposium on Compound Semiconductors (ISCS 2015), Jun 2015, Santa Barbara, CA, Poster Presentation.
      21. H. Fu, Z. Lu, and Y. Zhao, “The modeling of low-droop semipolar InGaN light emitting diodes with weak phase-space filling effect”, The 57th TMS Electronic Materials Conference (EMC 2015), Jun 2015,Columbus, OH, Oral Presentation.
      22. S. Marcinkevicius, R. Ivanov, Y. Zhao, S. Nakamura, S. P.DenBaars, and J. S. Speck, “Spatial variations of optical properties of semipolar InGaN quantum wells”, Photonics West 2015, Feb 2015, San Francisco, CA, Oral Presentation.
      23. S. Marcinkevicius, Y. Zhao, S. Nakamura, S. P.DenBaars, and J. S. Speck, “Optical properties of semipolar (20-2-1) InGaN/GaN quantum wells”, 2014 International Workshop on Nitride Semiconductors (IWN 2014), Aug 2014, Wroclaw, Poland, Oral Presentation.
      24. S. Marcinkevicius, Y. Zhao, K. Kelchner, S. Nakamura, S. P.DenBaars, and J. S. Speck, “Near‐field optical spectroscopy of band potential variations innonpolar and semipolar InGaN quantum wells”, The 41st International Symposium on Compound Semiconductors (ISCS 2014), May 2014, Montpellier, France, Oral Presentation.
      25. Y. Zhao, F. Wu, S. Nakamura, and J. S. Speck, “Structure characterization of atomic scale nanofacet in semipolar (20-2-1) and (20-21) InGaN single quantum well”, The 56th TMS Electronic Materials Conference (EMC 2014), Jun 2014, Santa Barbara, CA, Oral Presentation.
      26. D. L. Becerra,Y. Zhao, S. H. Oh, C. D. Pynn, J. S. Speck, S. P. DenBaars, and S. Nakamura, “Growth and characterization of semipolar (30-3-1) InGaN light-emitting diodes with high power and low efficiency droop”, The 56th TMS Electronic Materials Conference (EMC 2014), Jun 2014, Santa Barbara, CA, Oral Presentation.
      27. Y. Zhao, F. Wu, J. S. Speck, S. P. DenBaars, and S. Nakamura, “Growth and characterization of semipolar (20-2-1) green InGaN light-emitting diodes”, The 55th TMS Electronic Materials Conference (EMC 2013), Jun 2013, University of Notre Dame, IN, Oral Presentation.
      28. Y. Zhao, C. Y. Huang, C. C. Pan, S. Tanaka, Y. Kawaguchi, K. Fujito, D. Feezell, J. S. Speck, S. P. DenBaars, and S. Nakamura, “Semipolar (20-2-1) InGaN light-emitting diodes and laser diodes”, 2012 International Workshop on Nitride Semiconductors (IWN 2012), Oct2012, Sapporo, Japan, Oral Presentation.
      29. C. Y. Huang, Y. Zhao, Q. Yan, Y. Kawaguchi, Y. R. Wu, D. Feezell, C. G. Van de Walle, J. S. Speck, S. P. DenBaars, and S. Nakamura, “Carrier transports in semipolar multiple-quantum-wells light-emitting diodes”, 2012 International Workshop on Nitride Semiconductors (IWN 2012), Oct 2012, Sapporo, Japan, Oral Presentation.
      30. C. Y. Huang, M. T. Hardy, Y. Zhao, Q. Yan, A. Pourhashemi, D. Feezell, J. S. Speck, S. P. DenBaars, and S. Nakamura, “Semipolar (20-2-1) blue to aquamarine laser diodes with minimal wavelength blueshift”, 2012 International Workshop on Nitride Semiconductors (IWN 2012), Oct 2012, Sapporo, Japan, Oral Presentation. (Nominated for best paper award.)
      31. C. Y. Huang, Y. Zhao, F. Wu, Y. Kawaguchi, D. Feezell, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Growth characteristics of InGaN/GaN quantum wells on semipolar (20-21) and (20-2-1) planes”, 2012 International Workshop on Nitride Semiconductors (IWN 2012), Oct 2012, Sapporo, Japan, Post Presentation.
      32. C. C. Pan, S. Tanaka, F. Wu, Y. Zhao, J. S. Speck, S. Nakamura, S. P. DenBaars, and D. Feezell, “High-power, low-efficiency-droop semipolar (20-2-1) single-quantum-well blue light-emitting diodes”, 2012 International Workshop on Nitride Semiconductors (IWN 2012), Oct 2012, Sapporo, Japan, Poster Presentation.
      33. Y. Zhao, Q. Yan, D. Feezell, K. Fujito, C. G. Van de Walle, J. S. Speck, S. P. DenBaars, and S. Nakamura, “Optical polarization characterization of semipolar (30-3-1) and (30-31) blue-green InGaN/GaN light-emitting diodes”, The 39th International Symposium on Compound Semiconductors (ISCS 2012), Aug 2012, Santa Barbara, CA, Oral Presentation.
      34. Y. Zhao, C. Y. Huang, S. Tanaka, C. C. Pan, K. Fujito, D. Feezell, J. S. Speck, S. P. DenBaars, and S. Nakamura, “Semipolar (20-2-1) blue and green InGaN light-emitting diodes”, 2012 Conference on Lasers and Electro-Optics (CLEO 2012), May 2012, San Francisco, CA, Oral Presentation. (Nominated for best paper award & Highlighted as notable research breakthrough by American Institute of Physics and Optical Society of America & Reported by Science Magazine.)
      35. C. Y. Huang, Y. Zhao, M. T. Hardy, K. Fujito, D. Feezell, J. S. Speck, S. P. DenBaars, and S. Nakamura, “Semipolar (20-2-1) laser diodes (λ=505 nm) with wavelength stable InGaN/GaN quantum wells”, 2012 Conference on Lasers and Electro-Optics (CLEO 2012), May 2012, San Francisco, CA, Oral Presentation.
      36. D. Feezell, Y. Zhao, C. C. Pan, S. Tanaka, C. Y. Huang, F. Wu, J. S. Speck, S. P. DenBaars, and S. Nakamura, “Low droop and high efficiency semipolar (20-2-1) light-emitting diodes (LEDs)”, SPIE Photonics West 2012, Jan 2012, San Francisco, CA, Invited talk.
      37. Y. Zhao, S. Tanaka, C. C. Pan, K. Fujito, D. Feezell, J. S. Speck, S. P. DenBaars, and S. Nakamura, “High performance semipolar (20-2-1) InGaN/GaN light-emitting diodes”, 2011 Material Research Society Fall Meeting (MRS Fall 2011), Nov 2011, Boston, MA, Oral Presentation.
      38. Y. Zhao, S. Tanaka, R. B. Chung, C. C. Pan, K. Fujito, D. Feezell, J. S. Speck, S. P. DenBaars, and S. Nakamura, “Highly polarized spontaneous emission from semipolar (20-2-1) InGaN/GaN light-emitting diodes”, The 53rd TMS Electronic Materials Conference (EMC 2011), Jun 2011, Santa Barbara, CA, Oral Presentation.
      39. Y. Zhao, J. Sonoda, I. Koslow, C. C. Pan, S. Yamamoto, K. Fujito, H. Ohto, J. S. Ha, S. P. DenBaars, and S. Nakamura, “High internal and extraction efficiency in semipolar GaN-based LEDs”, 2010 International Workshop on Nitride Semiconductor (IWN 2010), Sep 2010, Tampa, FL, Oral Presentation.
      40. I. Koslow, J. Richardson, J. Sonoda, C. C. Pan, Y. Zhao, J. S. Ha, F. Lange, S. Nakamura, S. P. DenBaars, “Light-emitting diodes with ZnO current spreading layers grown by aqueous solution on various crystallographic planes of GaN”, 2010 International Workshop on Nitride Semiconductor (IWN 2010), Sep 2010, Tampa, FL, Poster Presentation.