Enhancing the Luminous Efficiency of Ultraviolet Light Emitting Diodes By Adjusting the Al Composition of Pre-Well Superlattice
The lower luminous efficiency is a critical issue for ultraviolet light-emitting diodes (UV-LEDs) owing to the poor carrier injection efficiency and high dislocation density. Here, we can improve the luminous efficiency in two avenues by adjusting the Al composition of the InGaN/Al<sub...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IEEE
2021-01-01
|
| Series: | IEEE Photonics Journal |
| Subjects: | |
| Online Access: | https://ieeexplore.ieee.org/document/9451621/ |
| _version_ | 1811339304636514304 |
|---|---|
| author | Yanli Wang Peixian Li Siyu Jiang Xiaowei Zhou Jinxing Wu Wenkai Yue Yue Hao |
| author_facet | Yanli Wang Peixian Li Siyu Jiang Xiaowei Zhou Jinxing Wu Wenkai Yue Yue Hao |
| author_sort | Yanli Wang |
| collection | DOAJ |
| description | The lower luminous efficiency is a critical issue for ultraviolet light-emitting diodes (UV-LEDs) owing to the poor carrier injection efficiency and high dislocation density. Here, we can improve the luminous efficiency in two avenues by adjusting the Al composition of the InGaN/Al<sub>x</sub>Ga<sub>1-x</sub>N pre-well superlattice. First, due to the strain-induced piezoelectric and intrinsic spontaneous polarization, a large number of electrons gather at the InGaN/Al<sub>x</sub>Ga<sub>1-x</sub>N interface, which improves the electron concentration of the pre-well superlattice and lowers the conduction band energy of the first quantum barrier layer (FQB), thus enhancing the electron injection efficiency. Second, the pre-well superlattice can act as a hole blocking layer to prevent holes from leaking into the n-type layer and confine them in the quantum well layer. As the Al composition increases, the hole blocking effect of the pre-well superlattice is strengthened. However, higher Al composition decreases the lattice quality, which makes it possible for carrier loss through defect-related non-radiative recombination. Finally, the output power of the samples with 5% Al composition in the pre-well superlattice is 5.9% and 102.5% higher than that of the samples with 3% and 7% Al composition, respectively. |
| first_indexed | 2024-04-13T18:24:26Z |
| format | Article |
| id | doaj.art-32d71538664c49f298560196e8e69b85 |
| institution | Directory Open Access Journal |
| issn | 1943-0655 |
| language | English |
| last_indexed | 2024-04-13T18:24:26Z |
| publishDate | 2021-01-01 |
| publisher | IEEE |
| record_format | Article |
| series | IEEE Photonics Journal |
| spelling | doaj.art-32d71538664c49f298560196e8e69b852022-12-22T02:35:19ZengIEEEIEEE Photonics Journal1943-06552021-01-011351610.1109/JPHOT.2021.30882229451621Enhancing the Luminous Efficiency of Ultraviolet Light Emitting Diodes By Adjusting the Al Composition of Pre-Well SuperlatticeYanli Wang0https://orcid.org/0000-0003-4830-3070Peixian Li1Siyu Jiang2Xiaowei Zhou3Jinxing Wu4https://orcid.org/0000-0002-2271-1749Wenkai Yue5Yue Hao6Wide Bandgap Semiconductor Technology Disciplines State Key Laboratory, School of Advanced Materials and Nanotechnology, Xidian University, Xi'an, ChinaWide Bandgap Semiconductor Technology Disciplines State Key Laboratory, School of Advanced Materials and Nanotechnology, Xidian University, Xi'an, ChinaWide Bandgap Semiconductor Technology Disciplines State Key Laboratory, School of Advanced Materials and Nanotechnology, Xidian University, Xi'an, ChinaWide Bandgap Semiconductor Technology Disciplines State Key Laboratory, School of Advanced Materials and Nanotechnology, Xidian University, Xi'an, ChinaWide Bandgap Semiconductor Technology Disciplines State Key Laboratory, School of Advanced Materials and Nanotechnology, Xidian University, Xi'an, ChinaWide Bandgap Semiconductor Technology Disciplines State Key Laboratory, School of Advanced Materials and Nanotechnology, Xidian University, Xi'an, ChinaWide Bandgap Semiconductor Technology Disciplines State Key Laboratory, School of Microelectronics, Xidian University, Xi'an, ChinaThe lower luminous efficiency is a critical issue for ultraviolet light-emitting diodes (UV-LEDs) owing to the poor carrier injection efficiency and high dislocation density. Here, we can improve the luminous efficiency in two avenues by adjusting the Al composition of the InGaN/Al<sub>x</sub>Ga<sub>1-x</sub>N pre-well superlattice. First, due to the strain-induced piezoelectric and intrinsic spontaneous polarization, a large number of electrons gather at the InGaN/Al<sub>x</sub>Ga<sub>1-x</sub>N interface, which improves the electron concentration of the pre-well superlattice and lowers the conduction band energy of the first quantum barrier layer (FQB), thus enhancing the electron injection efficiency. Second, the pre-well superlattice can act as a hole blocking layer to prevent holes from leaking into the n-type layer and confine them in the quantum well layer. As the Al composition increases, the hole blocking effect of the pre-well superlattice is strengthened. However, higher Al composition decreases the lattice quality, which makes it possible for carrier loss through defect-related non-radiative recombination. Finally, the output power of the samples with 5% Al composition in the pre-well superlattice is 5.9% and 102.5% higher than that of the samples with 3% and 7% Al composition, respectively.https://ieeexplore.ieee.org/document/9451621/Ultraviolet light-emitting diodeshole blocking layersuperlatticeAPSYS |
| spellingShingle | Yanli Wang Peixian Li Siyu Jiang Xiaowei Zhou Jinxing Wu Wenkai Yue Yue Hao Enhancing the Luminous Efficiency of Ultraviolet Light Emitting Diodes By Adjusting the Al Composition of Pre-Well Superlattice IEEE Photonics Journal Ultraviolet light-emitting diodes hole blocking layer superlattice APSYS |
| title | Enhancing the Luminous Efficiency of Ultraviolet Light Emitting Diodes By Adjusting the Al Composition of Pre-Well Superlattice |
| title_full | Enhancing the Luminous Efficiency of Ultraviolet Light Emitting Diodes By Adjusting the Al Composition of Pre-Well Superlattice |
| title_fullStr | Enhancing the Luminous Efficiency of Ultraviolet Light Emitting Diodes By Adjusting the Al Composition of Pre-Well Superlattice |
| title_full_unstemmed | Enhancing the Luminous Efficiency of Ultraviolet Light Emitting Diodes By Adjusting the Al Composition of Pre-Well Superlattice |
| title_short | Enhancing the Luminous Efficiency of Ultraviolet Light Emitting Diodes By Adjusting the Al Composition of Pre-Well Superlattice |
| title_sort | enhancing the luminous efficiency of ultraviolet light emitting diodes by adjusting the al composition of pre well superlattice |
| topic | Ultraviolet light-emitting diodes hole blocking layer superlattice APSYS |
| url | https://ieeexplore.ieee.org/document/9451621/ |
| work_keys_str_mv | AT yanliwang enhancingtheluminousefficiencyofultravioletlightemittingdiodesbyadjustingthealcompositionofprewellsuperlattice AT peixianli enhancingtheluminousefficiencyofultravioletlightemittingdiodesbyadjustingthealcompositionofprewellsuperlattice AT siyujiang enhancingtheluminousefficiencyofultravioletlightemittingdiodesbyadjustingthealcompositionofprewellsuperlattice AT xiaoweizhou enhancingtheluminousefficiencyofultravioletlightemittingdiodesbyadjustingthealcompositionofprewellsuperlattice AT jinxingwu enhancingtheluminousefficiencyofultravioletlightemittingdiodesbyadjustingthealcompositionofprewellsuperlattice AT wenkaiyue enhancingtheluminousefficiencyofultravioletlightemittingdiodesbyadjustingthealcompositionofprewellsuperlattice AT yuehao enhancingtheluminousefficiencyofultravioletlightemittingdiodesbyadjustingthealcompositionofprewellsuperlattice |