Understanding the origin of mobility enhancement in wedge-shaped c-GaN nanowall networks utilizing spectroscopic techniques
Recently, the electron mobility in wedge-shaped c-GaN nanowall networks has been estimated to cross the theoretical mobility limit for bulk GaN. Significant blue-shift of the bandgap has also been observed. Both the findings are explained in terms of two-dimensional electron gas (2DEG) formed at the...
Gespeichert in:
Veröffentlicht in: | Journal of applied physics 2022-11, Vol.132 (19) |
---|---|
Hauptverfasser: | , , , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
container_end_page | |
---|---|
container_issue | 19 |
container_start_page | |
container_title | Journal of applied physics |
container_volume | 132 |
creator | Kaur, Amandeep Bera, Kousik Yadav, Santosh Kumar Shivaprasad, S. M. Roy, Anushree Dhar, Subhabrata |
description | Recently, the electron mobility in wedge-shaped c-GaN nanowall networks has been estimated to cross the theoretical mobility limit for bulk GaN. Significant blue-shift of the bandgap has also been observed. Both the findings are explained in terms of two-dimensional electron gas (2DEG) formed at the central vertical plane of the walls due to the polarization charges at the two inclined faces. Carrier concentration and mobility have earlier been determined from thermoelectric power and conductivity measurements with the help of a statistical model. Due to the network nature of the system, direct measurements of these quantities from Hall experiments are not possible. Search for a better way to estimate mobility in this system thus becomes important. Since, strain can also lead to the blue-shift of the bandgap, it is also imperative to evaluate carefully the role of strain. Here, using Raman spectroscopy, we have estimated carrier concentration and mobility in these nanowall networks with varied average tip-widths. Depth distribution of strain and luminescence characteristics are also studied. The study reveals that strain has no role in the bandgap enhancement. Moreover, the electron mobility, which is determined from the lineshape analysis of the A1(LO)-plasmon coupled mode in Raman spectra, has been found to be significantly higher than the theoretical limit of mobility for bulk GaN for the same electron concentration. These results thus corroborate the picture of polarization induced vertical 2DEG formation in these walls as predicted theoretically. |
doi_str_mv | 10.1063/5.0122101 |
format | Article |
fullrecord | <record><control><sourceid>proquest_scita</sourceid><recordid>TN_cdi_proquest_journals_2737234675</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><sourcerecordid>2737234675</sourcerecordid><originalsourceid>FETCH-LOGICAL-c257t-a56b9f3445512a6dcce253b4dcdf9b78830f23e0f7495797a108c25c566bdd023</originalsourceid><addsrcrecordid>eNp9kM1KAzEUhYMoWKsL3yDgSmFqfiaTmaUUrULRjV2HTJLppLbJmKSW6ss7pUUXgqu7uN85594DwCVGI4wKestGCBOCET4CA4zKKuOMoWMwQIjgrKx4dQrOYlwghHFJqwH4mjltQkzSaevmMLUG-mDn1kHfwJWv7dKmLTSulU6ZlXEJ9quN0XOTxVZ2RkOVTeQzdNL5jVwuoTNp48NbhOvUaz93prEzKgUfle-sgsmo1tn3tYnn4KSRy2guDnMIZg_3r-PHbPoyeRrfTTNFGE-ZZEVdNTTPGcNEFlopQxitc610U9W8LClqCDWo4XnFeMVl_3evVKwoaq0RoUNwtfftgt_lJrHw6-D6SEE45YTmBWc9db2nVH9qDKYRXbArGbYCI7HrVjBx6LZnb_ZsVDbJZL37gT98-AVFp5v_4L_O3zlgib0</addsrcrecordid><sourcetype>Aggregation Database</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype><pqid>2737234675</pqid></control><display><type>article</type><title>Understanding the origin of mobility enhancement in wedge-shaped c-GaN nanowall networks utilizing spectroscopic techniques</title><source>AIP Journals Complete</source><source>Alma/SFX Local Collection</source><creator>Kaur, Amandeep ; Bera, Kousik ; Yadav, Santosh Kumar ; Shivaprasad, S. M. ; Roy, Anushree ; Dhar, Subhabrata</creator><creatorcontrib>Kaur, Amandeep ; Bera, Kousik ; Yadav, Santosh Kumar ; Shivaprasad, S. M. ; Roy, Anushree ; Dhar, Subhabrata</creatorcontrib><description>Recently, the electron mobility in wedge-shaped c-GaN nanowall networks has been estimated to cross the theoretical mobility limit for bulk GaN. Significant blue-shift of the bandgap has also been observed. Both the findings are explained in terms of two-dimensional electron gas (2DEG) formed at the central vertical plane of the walls due to the polarization charges at the two inclined faces. Carrier concentration and mobility have earlier been determined from thermoelectric power and conductivity measurements with the help of a statistical model. Due to the network nature of the system, direct measurements of these quantities from Hall experiments are not possible. Search for a better way to estimate mobility in this system thus becomes important. Since, strain can also lead to the blue-shift of the bandgap, it is also imperative to evaluate carefully the role of strain. Here, using Raman spectroscopy, we have estimated carrier concentration and mobility in these nanowall networks with varied average tip-widths. Depth distribution of strain and luminescence characteristics are also studied. The study reveals that strain has no role in the bandgap enhancement. Moreover, the electron mobility, which is determined from the lineshape analysis of the A1(LO)-plasmon coupled mode in Raman spectra, has been found to be significantly higher than the theoretical limit of mobility for bulk GaN for the same electron concentration. These results thus corroborate the picture of polarization induced vertical 2DEG formation in these walls as predicted theoretically.</description><identifier>ISSN: 0021-8979</identifier><identifier>EISSN: 1089-7550</identifier><identifier>DOI: 10.1063/5.0122101</identifier><identifier>CODEN: JAPIAU</identifier><language>eng</language><publisher>Melville: American Institute of Physics</publisher><subject>Blue shift ; Carrier density ; Coupled modes ; Electron gas ; Electron mobility ; Energy gap ; Networks ; Raman spectra ; Raman spectroscopy ; Spectrum analysis ; Statistical models ; Vertical polarization</subject><ispartof>Journal of applied physics, 2022-11, Vol.132 (19)</ispartof><rights>Author(s)</rights><rights>2022 Author(s). Published under an exclusive license by AIP Publishing.</rights><lds50>peer_reviewed</lds50><woscitedreferencessubscribed>false</woscitedreferencessubscribed><citedby>FETCH-LOGICAL-c257t-a56b9f3445512a6dcce253b4dcdf9b78830f23e0f7495797a108c25c566bdd023</citedby><cites>FETCH-LOGICAL-c257t-a56b9f3445512a6dcce253b4dcdf9b78830f23e0f7495797a108c25c566bdd023</cites><orcidid>0000-0002-8399-3815 ; 0000-0001-8911-9515 ; 0000-0003-1530-4819</orcidid></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><linktohtml>$$Uhttps://pubs.aip.org/jap/article-lookup/doi/10.1063/5.0122101$$EHTML$$P50$$Gscitation$$H</linktohtml><link.rule.ids>314,776,780,790,4498,27901,27902,76126</link.rule.ids></links><search><creatorcontrib>Kaur, Amandeep</creatorcontrib><creatorcontrib>Bera, Kousik</creatorcontrib><creatorcontrib>Yadav, Santosh Kumar</creatorcontrib><creatorcontrib>Shivaprasad, S. M.</creatorcontrib><creatorcontrib>Roy, Anushree</creatorcontrib><creatorcontrib>Dhar, Subhabrata</creatorcontrib><title>Understanding the origin of mobility enhancement in wedge-shaped c-GaN nanowall networks utilizing spectroscopic techniques</title><title>Journal of applied physics</title><description>Recently, the electron mobility in wedge-shaped c-GaN nanowall networks has been estimated to cross the theoretical mobility limit for bulk GaN. Significant blue-shift of the bandgap has also been observed. Both the findings are explained in terms of two-dimensional electron gas (2DEG) formed at the central vertical plane of the walls due to the polarization charges at the two inclined faces. Carrier concentration and mobility have earlier been determined from thermoelectric power and conductivity measurements with the help of a statistical model. Due to the network nature of the system, direct measurements of these quantities from Hall experiments are not possible. Search for a better way to estimate mobility in this system thus becomes important. Since, strain can also lead to the blue-shift of the bandgap, it is also imperative to evaluate carefully the role of strain. Here, using Raman spectroscopy, we have estimated carrier concentration and mobility in these nanowall networks with varied average tip-widths. Depth distribution of strain and luminescence characteristics are also studied. The study reveals that strain has no role in the bandgap enhancement. Moreover, the electron mobility, which is determined from the lineshape analysis of the A1(LO)-plasmon coupled mode in Raman spectra, has been found to be significantly higher than the theoretical limit of mobility for bulk GaN for the same electron concentration. These results thus corroborate the picture of polarization induced vertical 2DEG formation in these walls as predicted theoretically.</description><subject>Blue shift</subject><subject>Carrier density</subject><subject>Coupled modes</subject><subject>Electron gas</subject><subject>Electron mobility</subject><subject>Energy gap</subject><subject>Networks</subject><subject>Raman spectra</subject><subject>Raman spectroscopy</subject><subject>Spectrum analysis</subject><subject>Statistical models</subject><subject>Vertical polarization</subject><issn>0021-8979</issn><issn>1089-7550</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2022</creationdate><recordtype>article</recordtype><recordid>eNp9kM1KAzEUhYMoWKsL3yDgSmFqfiaTmaUUrULRjV2HTJLppLbJmKSW6ss7pUUXgqu7uN85594DwCVGI4wKestGCBOCET4CA4zKKuOMoWMwQIjgrKx4dQrOYlwghHFJqwH4mjltQkzSaevmMLUG-mDn1kHfwJWv7dKmLTSulU6ZlXEJ9quN0XOTxVZ2RkOVTeQzdNL5jVwuoTNp48NbhOvUaz93prEzKgUfle-sgsmo1tn3tYnn4KSRy2guDnMIZg_3r-PHbPoyeRrfTTNFGE-ZZEVdNTTPGcNEFlopQxitc610U9W8LClqCDWo4XnFeMVl_3evVKwoaq0RoUNwtfftgt_lJrHw6-D6SEE45YTmBWc9db2nVH9qDKYRXbArGbYCI7HrVjBx6LZnb_ZsVDbJZL37gT98-AVFp5v_4L_O3zlgib0</recordid><startdate>20221121</startdate><enddate>20221121</enddate><creator>Kaur, Amandeep</creator><creator>Bera, Kousik</creator><creator>Yadav, Santosh Kumar</creator><creator>Shivaprasad, S. M.</creator><creator>Roy, Anushree</creator><creator>Dhar, Subhabrata</creator><general>American Institute of Physics</general><scope>AAYXX</scope><scope>CITATION</scope><scope>8FD</scope><scope>H8D</scope><scope>L7M</scope><orcidid>https://orcid.org/0000-0002-8399-3815</orcidid><orcidid>https://orcid.org/0000-0001-8911-9515</orcidid><orcidid>https://orcid.org/0000-0003-1530-4819</orcidid></search><sort><creationdate>20221121</creationdate><title>Understanding the origin of mobility enhancement in wedge-shaped c-GaN nanowall networks utilizing spectroscopic techniques</title><author>Kaur, Amandeep ; Bera, Kousik ; Yadav, Santosh Kumar ; Shivaprasad, S. M. ; Roy, Anushree ; Dhar, Subhabrata</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-c257t-a56b9f3445512a6dcce253b4dcdf9b78830f23e0f7495797a108c25c566bdd023</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>2022</creationdate><topic>Blue shift</topic><topic>Carrier density</topic><topic>Coupled modes</topic><topic>Electron gas</topic><topic>Electron mobility</topic><topic>Energy gap</topic><topic>Networks</topic><topic>Raman spectra</topic><topic>Raman spectroscopy</topic><topic>Spectrum analysis</topic><topic>Statistical models</topic><topic>Vertical polarization</topic><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Kaur, Amandeep</creatorcontrib><creatorcontrib>Bera, Kousik</creatorcontrib><creatorcontrib>Yadav, Santosh Kumar</creatorcontrib><creatorcontrib>Shivaprasad, S. M.</creatorcontrib><creatorcontrib>Roy, Anushree</creatorcontrib><creatorcontrib>Dhar, Subhabrata</creatorcontrib><collection>CrossRef</collection><collection>Technology Research Database</collection><collection>Aerospace Database</collection><collection>Advanced Technologies Database with Aerospace</collection><jtitle>Journal of applied physics</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>Kaur, Amandeep</au><au>Bera, Kousik</au><au>Yadav, Santosh Kumar</au><au>Shivaprasad, S. M.</au><au>Roy, Anushree</au><au>Dhar, Subhabrata</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Understanding the origin of mobility enhancement in wedge-shaped c-GaN nanowall networks utilizing spectroscopic techniques</atitle><jtitle>Journal of applied physics</jtitle><date>2022-11-21</date><risdate>2022</risdate><volume>132</volume><issue>19</issue><issn>0021-8979</issn><eissn>1089-7550</eissn><coden>JAPIAU</coden><abstract>Recently, the electron mobility in wedge-shaped c-GaN nanowall networks has been estimated to cross the theoretical mobility limit for bulk GaN. Significant blue-shift of the bandgap has also been observed. Both the findings are explained in terms of two-dimensional electron gas (2DEG) formed at the central vertical plane of the walls due to the polarization charges at the two inclined faces. Carrier concentration and mobility have earlier been determined from thermoelectric power and conductivity measurements with the help of a statistical model. Due to the network nature of the system, direct measurements of these quantities from Hall experiments are not possible. Search for a better way to estimate mobility in this system thus becomes important. Since, strain can also lead to the blue-shift of the bandgap, it is also imperative to evaluate carefully the role of strain. Here, using Raman spectroscopy, we have estimated carrier concentration and mobility in these nanowall networks with varied average tip-widths. Depth distribution of strain and luminescence characteristics are also studied. The study reveals that strain has no role in the bandgap enhancement. Moreover, the electron mobility, which is determined from the lineshape analysis of the A1(LO)-plasmon coupled mode in Raman spectra, has been found to be significantly higher than the theoretical limit of mobility for bulk GaN for the same electron concentration. These results thus corroborate the picture of polarization induced vertical 2DEG formation in these walls as predicted theoretically.</abstract><cop>Melville</cop><pub>American Institute of Physics</pub><doi>10.1063/5.0122101</doi><tpages>9</tpages><orcidid>https://orcid.org/0000-0002-8399-3815</orcidid><orcidid>https://orcid.org/0000-0001-8911-9515</orcidid><orcidid>https://orcid.org/0000-0003-1530-4819</orcidid></addata></record> |
fulltext | fulltext |
identifier | ISSN: 0021-8979 |
ispartof | Journal of applied physics, 2022-11, Vol.132 (19) |
issn | 0021-8979 1089-7550 |
language | eng |
recordid | cdi_proquest_journals_2737234675 |
source | AIP Journals Complete; Alma/SFX Local Collection |
subjects | Blue shift Carrier density Coupled modes Electron gas Electron mobility Energy gap Networks Raman spectra Raman spectroscopy Spectrum analysis Statistical models Vertical polarization |
title | Understanding the origin of mobility enhancement in wedge-shaped c-GaN nanowall networks utilizing spectroscopic techniques |
url | https://sfx.bib-bvb.de/sfx_tum?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2025-02-07T13%3A15%3A17IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-proquest_scita&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Understanding%20the%20origin%20of%20mobility%20enhancement%20in%20wedge-shaped%20c-GaN%20nanowall%20networks%20utilizing%20spectroscopic%20techniques&rft.jtitle=Journal%20of%20applied%20physics&rft.au=Kaur,%20Amandeep&rft.date=2022-11-21&rft.volume=132&rft.issue=19&rft.issn=0021-8979&rft.eissn=1089-7550&rft.coden=JAPIAU&rft_id=info:doi/10.1063/5.0122101&rft_dat=%3Cproquest_scita%3E2737234675%3C/proquest_scita%3E%3Curl%3E%3C/url%3E&disable_directlink=true&sfx.directlink=off&sfx.report_link=0&rft_id=info:oai/&rft_pqid=2737234675&rft_id=info:pmid/&rfr_iscdi=true |