Improved Performance of GaN-Based Ultraviolet LEDs With Electron Blocking Layers Composed of Double-Peak <italic>p</italic>-Type Al<sub><italic>x</italic></sub>Ga<sub>1−<italic>x</italic></sub>N/GaN Superlattice Layers
Past studies have demonstrated the positive impact of step-graded <inline-formula> <tex-math notation="LaTeX">$p$ </tex-math></inline-formula>-type Al<sub><italic>x</italic></sub>Ga<sub>1−<italic>x</italic></su...
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| Format: | Article |
| Language: | English |
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IEEE
2021-01-01
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| Series: | IEEE Access |
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| Online Access: | https://ieeexplore.ieee.org/document/9416661/ |
| _version_ | 1818643311266627584 |
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| author | Yong Huang Zhiyou Guo Miao Zhang Dan Xiang |
| author_facet | Yong Huang Zhiyou Guo Miao Zhang Dan Xiang |
| author_sort | Yong Huang |
| collection | DOAJ |
| description | Past studies have demonstrated the positive impact of step-graded <inline-formula> <tex-math notation="LaTeX">$p$ </tex-math></inline-formula>-type Al<sub><italic>x</italic></sub>Ga<sub>1−<italic>x</italic></sub>N/GaN superlattice (SL) electron blocking layer (EBL) structures on the efficiency performance of ultraviolet (UV) GaN-based light-emitting diodes (LEDs). However, the optimal Al-grading structure of these SL EBLs remains unclear owing to a lack of systematic investigation. The present work addresses this issue by applying EBL composed of alternating half-peak, single-peak, and double-peak <inline-formula> <tex-math notation="LaTeX">$p$ </tex-math></inline-formula>-type Al<sub><italic>x</italic></sub>Ga<sub>1−<italic>x</italic></sub>N/GaN SL structures with varying values of <inline-formula> <tex-math notation="LaTeX">$x$ </tex-math></inline-formula> ranging from 0.05 to 0.15 in 0.05 step increments. Simulation analysis is employed to obtain the internal quantum efficiency (IQE), energy band diagrams, polarization compensation factor, hole concentration, and electron concentration of GaN-based UV LEDs with three different SL-EBL structures. The results obtained at an injection current of 200 mA demonstrate that UV LEDs with double-peak SL-EBL structures provide the maximum IQE, which is ~38% greater than that of devices employing the conventional EBL in simulation experiment. This SL-EBL is demonstrated to improve the hole injection and electron overflow performance of GaN-based UV LEDs owing to the polarization charge and lattice mismatch at the <italic>p-</italic>Al<sub><italic>x</italic></sub>Ga<sub>1−<italic>x</italic></sub>N/GaN interfaces. The reduced Al composition on the <italic>p-</italic>GaN side reduces the potential barrier of hole injection. Moreover, the predicted increase in the IQE of GaN-based UV LEDs with the optimal SL-EBL is verified experimentally. |
| first_indexed | 2024-12-16T23:56:56Z |
| format | Article |
| id | doaj.art-9823f400a02d41a9866337cbdc2a3f7c |
| institution | Directory Open Access Journal |
| issn | 2169-3536 |
| language | English |
| last_indexed | 2024-12-16T23:56:56Z |
| publishDate | 2021-01-01 |
| publisher | IEEE |
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| series | IEEE Access |
| spelling | doaj.art-9823f400a02d41a9866337cbdc2a3f7c2022-12-21T22:11:11ZengIEEEIEEE Access2169-35362021-01-019652466525310.1109/ACCESS.2021.30759919416661Improved Performance of GaN-Based Ultraviolet LEDs With Electron Blocking Layers Composed of Double-Peak <italic>p</italic>-Type Al<sub><italic>x</italic></sub>Ga<sub>1−<italic>x</italic></sub>N/GaN Superlattice LayersYong Huang0https://orcid.org/0000-0002-0309-6445Zhiyou Guo1https://orcid.org/0000-0001-5563-3719Miao Zhang2https://orcid.org/0000-0001-8732-4371Dan Xiang3https://orcid.org/0000-0001-9922-1599Guangdong Industrial Training Center, Guangdong Polytechnic Normal University, Guangzhou, ChinaInstitute of the Opto-Electronic Materials and Technology, South China Normal University, Guangzhou, ChinaInstitute of the Opto-Electronic Materials and Technology, South China Normal University, Guangzhou, ChinaGuangdong Industrial Training Center, Guangdong Polytechnic Normal University, Guangzhou, ChinaPast studies have demonstrated the positive impact of step-graded <inline-formula> <tex-math notation="LaTeX">$p$ </tex-math></inline-formula>-type Al<sub><italic>x</italic></sub>Ga<sub>1−<italic>x</italic></sub>N/GaN superlattice (SL) electron blocking layer (EBL) structures on the efficiency performance of ultraviolet (UV) GaN-based light-emitting diodes (LEDs). However, the optimal Al-grading structure of these SL EBLs remains unclear owing to a lack of systematic investigation. The present work addresses this issue by applying EBL composed of alternating half-peak, single-peak, and double-peak <inline-formula> <tex-math notation="LaTeX">$p$ </tex-math></inline-formula>-type Al<sub><italic>x</italic></sub>Ga<sub>1−<italic>x</italic></sub>N/GaN SL structures with varying values of <inline-formula> <tex-math notation="LaTeX">$x$ </tex-math></inline-formula> ranging from 0.05 to 0.15 in 0.05 step increments. Simulation analysis is employed to obtain the internal quantum efficiency (IQE), energy band diagrams, polarization compensation factor, hole concentration, and electron concentration of GaN-based UV LEDs with three different SL-EBL structures. The results obtained at an injection current of 200 mA demonstrate that UV LEDs with double-peak SL-EBL structures provide the maximum IQE, which is ~38% greater than that of devices employing the conventional EBL in simulation experiment. This SL-EBL is demonstrated to improve the hole injection and electron overflow performance of GaN-based UV LEDs owing to the polarization charge and lattice mismatch at the <italic>p-</italic>Al<sub><italic>x</italic></sub>Ga<sub>1−<italic>x</italic></sub>N/GaN interfaces. The reduced Al composition on the <italic>p-</italic>GaN side reduces the potential barrier of hole injection. Moreover, the predicted increase in the IQE of GaN-based UV LEDs with the optimal SL-EBL is verified experimentally.https://ieeexplore.ieee.org/document/9416661/Light emitting diodesultraviolet sourcessuperlattice electron blocking layers |
| spellingShingle | Yong Huang Zhiyou Guo Miao Zhang Dan Xiang Improved Performance of GaN-Based Ultraviolet LEDs With Electron Blocking Layers Composed of Double-Peak <italic>p</italic>-Type Al<sub><italic>x</italic></sub>Ga<sub>1−<italic>x</italic></sub>N/GaN Superlattice Layers IEEE Access Light emitting diodes ultraviolet sources superlattice electron blocking layers |
| title | Improved Performance of GaN-Based Ultraviolet LEDs With Electron Blocking Layers Composed of Double-Peak <italic>p</italic>-Type Al<sub><italic>x</italic></sub>Ga<sub>1−<italic>x</italic></sub>N/GaN Superlattice Layers |
| title_full | Improved Performance of GaN-Based Ultraviolet LEDs With Electron Blocking Layers Composed of Double-Peak <italic>p</italic>-Type Al<sub><italic>x</italic></sub>Ga<sub>1−<italic>x</italic></sub>N/GaN Superlattice Layers |
| title_fullStr | Improved Performance of GaN-Based Ultraviolet LEDs With Electron Blocking Layers Composed of Double-Peak <italic>p</italic>-Type Al<sub><italic>x</italic></sub>Ga<sub>1−<italic>x</italic></sub>N/GaN Superlattice Layers |
| title_full_unstemmed | Improved Performance of GaN-Based Ultraviolet LEDs With Electron Blocking Layers Composed of Double-Peak <italic>p</italic>-Type Al<sub><italic>x</italic></sub>Ga<sub>1−<italic>x</italic></sub>N/GaN Superlattice Layers |
| title_short | Improved Performance of GaN-Based Ultraviolet LEDs With Electron Blocking Layers Composed of Double-Peak <italic>p</italic>-Type Al<sub><italic>x</italic></sub>Ga<sub>1−<italic>x</italic></sub>N/GaN Superlattice Layers |
| title_sort | improved performance of gan based ultraviolet leds with electron blocking layers composed of double peak italic p italic type al sub italic x italic sub ga sub 1 x2212 italic x italic sub n gan superlattice layers |
| topic | Light emitting diodes ultraviolet sources superlattice electron blocking layers |
| url | https://ieeexplore.ieee.org/document/9416661/ |
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