Polarization self-screening in [0001] oriented InGaN/GaN light-emitting diodes for improving the electron injection efficiency

Zhang, Zi-Hui; Liu, Wei; Ju, Zhengang; Tiam Tan, Swee; Ji, Yun; Zhang, Xueliang; Wang, Liancheng; Kyaw, Zabu

doi:10.1063/1.4885421

Title: Polarization self-screening in [0001] oriented InGaN/GaN light-emitting diodes for improving the electron injection efficiency

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Abstract

InGaN/GaN light-emitting diodes (LEDs) grown along the [0001] orientation inherit very strong polarization induced electric fields. This results in a reduced effective conduction band barrier height for the p-type AlGaN electron blocking layer (EBL) and makes the electron blocking effect relatively ineffective and the electron injection efficiency drops. Here, we show the concept of polarization self-screening for improving the electron injection efficiency. In this work, the proposed polarization self-screening effect was studied and proven through growing a p-type EBL with AlN composition partially graded along the [0001] orientation, which induces the bulk polarization charges. These bulk polarization charges are utilized to effectively self-screen the positive polarization induced interface charges located at the interface between the EBL and the last quantum barrier when designed properly. Using this approach, the electron leakage is suppressed and the LED performance is enhanced significantly.

Authors:: Zhang, Zi-Hui; Liu, Wei; Ju, Zhengang; Tiam Tan, Swee; Ji, Yun; Zhang, Xueliang; Wang, Liancheng; Kyaw, Zabu

Publication Date:: Mon Jun 23 00:00:00 EDT 2014

OSTI Identifier:: 22303837

Resource Type:: Journal Article

Journal Name:: Applied Physics Letters

Additional Journal Information:: Journal Volume: 104; Journal Issue: 25; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0003-6951

Country of Publication:: United States

Language:: English

Subject:: 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM NITRIDES; DEPLETION LAYER; EFFICIENCY; ELECTRIC FIELDS; ELECTRON BEAM INJECTION; ELECTRON EMISSION; GALLIUM NITRIDES; HETEROJUNCTIONS; INDIUM COMPOUNDS; INTERFACES; LIGHT EMITTING DIODES; POLARIZATION; SCREENS

Citation Formats


                    Zhang, Zi-Hui, Liu, Wei, Ju, Zhengang, Tiam Tan, Swee, Ji, Yun, Zhang, Xueliang, Wang, Liancheng, Kyaw, Zabu, Wei Sun, Xiao, E-mail: exwsun@ntu.edu.sg, E-mail: volkan@stanfordalumni.org, Volkan Demir, Hilmi, E-mail: exwsun@ntu.edu.sg, E-mail: volkan@stanfordalumni.org, and Department of Electrical and Electronics, Department of Physics, and UNAM-Institute of Material Science and Nanotechnology, Bilkent University, TR-06800 Ankara. Polarization self-screening in [0001] oriented InGaN/GaN light-emitting diodes for improving the electron injection efficiency.  United States: N. p., 2014. 
        Web.  doi:10.1063/1.4885421.

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                    Zhang, Zi-Hui, Liu, Wei, Ju, Zhengang, Tiam Tan, Swee, Ji, Yun, Zhang, Xueliang, Wang, Liancheng, Kyaw, Zabu, Wei Sun, Xiao, E-mail: exwsun@ntu.edu.sg, E-mail: volkan@stanfordalumni.org, Volkan Demir, Hilmi, E-mail: exwsun@ntu.edu.sg, E-mail: volkan@stanfordalumni.org, & Department of Electrical and Electronics, Department of Physics, and UNAM-Institute of Material Science and Nanotechnology, Bilkent University, TR-06800 Ankara. Polarization self-screening in [0001] oriented InGaN/GaN light-emitting diodes for improving the electron injection efficiency.  United States.  https://doi.org/10.1063/1.4885421

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                    Zhang, Zi-Hui, Liu, Wei, Ju, Zhengang, Tiam Tan, Swee, Ji, Yun, Zhang, Xueliang, Wang, Liancheng, Kyaw, Zabu, Wei Sun, Xiao, E-mail: exwsun@ntu.edu.sg, E-mail: volkan@stanfordalumni.org, Volkan Demir, Hilmi, E-mail: exwsun@ntu.edu.sg, E-mail: volkan@stanfordalumni.org, and Department of Electrical and Electronics, Department of Physics, and UNAM-Institute of Material Science and Nanotechnology, Bilkent University, TR-06800 Ankara. 2014.  
        "Polarization self-screening in [0001] oriented InGaN/GaN light-emitting diodes for improving the electron injection efficiency".  United States.  https://doi.org/10.1063/1.4885421.

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@article{osti_22303837,

  title        = {Polarization self-screening in [0001] oriented InGaN/GaN light-emitting diodes for improving the electron injection efficiency},

  author       = {Zhang, Zi-Hui and Liu, Wei and Ju, Zhengang and Tiam Tan, Swee and Ji, Yun and Zhang, Xueliang and Wang, Liancheng and Kyaw, Zabu and Wei Sun, Xiao, E-mail: exwsun@ntu.edu.sg, E-mail: volkan@stanfordalumni.org and Volkan Demir, Hilmi, E-mail: exwsun@ntu.edu.sg, E-mail: volkan@stanfordalumni.org and Department of Electrical and Electronics, Department of Physics, and UNAM-Institute of Material Science and Nanotechnology, Bilkent University, TR-06800 Ankara},

  abstractNote = {InGaN/GaN light-emitting diodes (LEDs) grown along the [0001] orientation inherit very strong polarization induced electric fields. This results in a reduced effective conduction band barrier height for the p-type AlGaN electron blocking layer (EBL) and makes the electron blocking effect relatively ineffective and the electron injection efficiency drops. Here, we show the concept of polarization self-screening for improving the electron injection efficiency. In this work, the proposed polarization self-screening effect was studied and proven through growing a p-type EBL with AlN composition partially graded along the [0001] orientation, which induces the bulk polarization charges. These bulk polarization charges are utilized to effectively self-screen the positive polarization induced interface charges located at the interface between the EBL and the last quantum barrier when designed properly. Using this approach, the electron leakage is suppressed and the LED performance is enhanced significantly.},

  doi          = {10.1063/1.4885421},

  url          = {https://www.osti.gov/biblio/22303837},
  journal      = {Applied Physics Letters},

  issn         = {0003-6951},

  number       = 25,

  volume       = 104,

  place        = {United States},

  year         = {Mon Jun 23 00:00:00 EDT 2014},

  month        = {Mon Jun 23 00:00:00 EDT 2014}

}

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