Polarization Modulation at Last Quantum Barrier for High Efficiency AlGaN-Based UV LED
The performance of AlGaN-based light-emitting diodes (LEDs) emitting at UVA–UVC regions can be severely compromised due to the polarization difference (ΔP) between the last quantum barrier (LQB) and the electron blocking layer (EBL). In this work, the different situations of th...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IEEE
2022-01-01
|
| Series: | IEEE Photonics Journal |
| Subjects: | |
| Online Access: | https://ieeexplore.ieee.org/document/9665406/ |
| _version_ | 1818441044742635520 |
|---|---|
| author | Zhiyuan Liu Yi Lu Yue Wang Rongyu Lin Chenxin Xiong Xiaohang Li |
| author_facet | Zhiyuan Liu Yi Lu Yue Wang Rongyu Lin Chenxin Xiong Xiaohang Li |
| author_sort | Zhiyuan Liu |
| collection | DOAJ |
| description | The performance of AlGaN-based light-emitting diodes (LEDs) emitting at UVA–UVC regions can be severely compromised due to the polarization difference (ΔP) between the last quantum barrier (LQB) and the electron blocking layer (EBL). In this work, the different situations of the bandgap difference (ΔE<sub>g</sub>) and ΔP of InAlN/AlGaN and AlGaN/AlGaN heterojunctions fully strained on GaN and AlN substrates are discussed. It shows that the InAlN/AlGaN heterojunctions could produce positive or negative sheet charges at the heterointerface under ΔE<sub>g</sub> >0, which could not be realized by the conventional AlGaN/AlGaN heterojunctions. To demonstrate and utilize the feature, the polarization-modulated InAlN LQBs with 0.14–0.16 indium compositions of 320 nm UVB LEDs are designed and investigated. It is observed that the InAlN LQBs could replace the conventional AlGaN LQB to improve electron confinement and hole injection by affecting effective barrier heights. By modulating the LQB/EBL polarization using InAlN, the proposed UV LED has a 32% enhancement in internal quantum efficiency and lower efficiency droop (from 16.9% to 0.7%) compared with the conventional one without modulation. The operation voltage at the same current also significantly decreases. The improvement of optical output power and wall plug efficiency at 60 mA in proposed structures are near 90% and 100%, respectively. This study provides a novel and highly effective methodology for development of high efficiency UV LEDs. |
| first_indexed | 2024-12-14T18:22:00Z |
| format | Article |
| id | doaj.art-e8a05f05d34c46bf935d790e6bca1f88 |
| institution | Directory Open Access Journal |
| issn | 1943-0655 |
| language | English |
| last_indexed | 2024-12-14T18:22:00Z |
| publishDate | 2022-01-01 |
| publisher | IEEE |
| record_format | Article |
| series | IEEE Photonics Journal |
| spelling | doaj.art-e8a05f05d34c46bf935d790e6bca1f882022-12-21T22:52:02ZengIEEEIEEE Photonics Journal1943-06552022-01-011411810.1109/JPHOT.2021.31392659665406Polarization Modulation at Last Quantum Barrier for High Efficiency AlGaN-Based UV LEDZhiyuan Liu0https://orcid.org/0000-0002-8690-2069Yi Lu1https://orcid.org/0000-0002-6197-1471Yue Wang2Rongyu Lin3Chenxin Xiong4Xiaohang Li5https://orcid.org/0000-0002-4434-365XAdvanced Semiconductor Laboratory, King Abdullah University of Science and Technology, Thuwal, Saudi ArabiaAdvanced Semiconductor Laboratory, King Abdullah University of Science and Technology, Thuwal, Saudi ArabiaAdvanced Semiconductor Laboratory, King Abdullah University of Science and Technology, Thuwal, Saudi ArabiaAdvanced Semiconductor Laboratory, King Abdullah University of Science and Technology, Thuwal, Saudi ArabiaAdvanced Semiconductor Laboratory, King Abdullah University of Science and Technology, Thuwal, Saudi ArabiaAdvanced Semiconductor Laboratory, King Abdullah University of Science and Technology, Thuwal, Saudi ArabiaThe performance of AlGaN-based light-emitting diodes (LEDs) emitting at UVA–UVC regions can be severely compromised due to the polarization difference (ΔP) between the last quantum barrier (LQB) and the electron blocking layer (EBL). In this work, the different situations of the bandgap difference (ΔE<sub>g</sub>) and ΔP of InAlN/AlGaN and AlGaN/AlGaN heterojunctions fully strained on GaN and AlN substrates are discussed. It shows that the InAlN/AlGaN heterojunctions could produce positive or negative sheet charges at the heterointerface under ΔE<sub>g</sub> >0, which could not be realized by the conventional AlGaN/AlGaN heterojunctions. To demonstrate and utilize the feature, the polarization-modulated InAlN LQBs with 0.14–0.16 indium compositions of 320 nm UVB LEDs are designed and investigated. It is observed that the InAlN LQBs could replace the conventional AlGaN LQB to improve electron confinement and hole injection by affecting effective barrier heights. By modulating the LQB/EBL polarization using InAlN, the proposed UV LED has a 32% enhancement in internal quantum efficiency and lower efficiency droop (from 16.9% to 0.7%) compared with the conventional one without modulation. The operation voltage at the same current also significantly decreases. The improvement of optical output power and wall plug efficiency at 60 mA in proposed structures are near 90% and 100%, respectively. This study provides a novel and highly effective methodology for development of high efficiency UV LEDs.https://ieeexplore.ieee.org/document/9665406/AlGaN-based UV LEDelectron blockinghole injectionindium aluminum nitridelast quantum barrierpolarization |
| spellingShingle | Zhiyuan Liu Yi Lu Yue Wang Rongyu Lin Chenxin Xiong Xiaohang Li Polarization Modulation at Last Quantum Barrier for High Efficiency AlGaN-Based UV LED IEEE Photonics Journal AlGaN-based UV LED electron blocking hole injection indium aluminum nitride last quantum barrier polarization |
| title | Polarization Modulation at Last Quantum Barrier for High Efficiency AlGaN-Based UV LED |
| title_full | Polarization Modulation at Last Quantum Barrier for High Efficiency AlGaN-Based UV LED |
| title_fullStr | Polarization Modulation at Last Quantum Barrier for High Efficiency AlGaN-Based UV LED |
| title_full_unstemmed | Polarization Modulation at Last Quantum Barrier for High Efficiency AlGaN-Based UV LED |
| title_short | Polarization Modulation at Last Quantum Barrier for High Efficiency AlGaN-Based UV LED |
| title_sort | polarization modulation at last quantum barrier for high efficiency algan based uv led |
| topic | AlGaN-based UV LED electron blocking hole injection indium aluminum nitride last quantum barrier polarization |
| url | https://ieeexplore.ieee.org/document/9665406/ |
| work_keys_str_mv | AT zhiyuanliu polarizationmodulationatlastquantumbarrierforhighefficiencyalganbaseduvled AT yilu polarizationmodulationatlastquantumbarrierforhighefficiencyalganbaseduvled AT yuewang polarizationmodulationatlastquantumbarrierforhighefficiencyalganbaseduvled AT rongyulin polarizationmodulationatlastquantumbarrierforhighefficiencyalganbaseduvled AT chenxinxiong polarizationmodulationatlastquantumbarrierforhighefficiencyalganbaseduvled AT xiaohangli polarizationmodulationatlastquantumbarrierforhighefficiencyalganbaseduvled |