Band structure properties, phonons, and exciton fine structure in 4H-SiC measured by wavelength-modulated absorption and low-temperature photoluminescence

Owing to its hexagonal symmetry, indirect band gap, and relatively large unit cell, the electronic band structure of 4H-SiC is comprised of a complicated series of anisotropic valence and conduction band extrema even very near to the uppermost valence band maximum and lowest conduction band minimum....

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Physical review. B 2020-11, Vol.102 (20), p.205203
Hauptverfasser: Klahold, W M, Choyke, W J, Devaty, R P
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
container_end_page
container_issue 20
container_start_page 205203
container_title Physical review. B
container_volume 102
creator Klahold, W M
Choyke, W J
Devaty, R P
description Owing to its hexagonal symmetry, indirect band gap, and relatively large unit cell, the electronic band structure of 4H-SiC is comprised of a complicated series of anisotropic valence and conduction band extrema even very near to the uppermost valence band maximum and lowest conduction band minimum. This has presented a difficult challenge to those experiments which have attempted to resolve the small energy separations between these band extrema. To overcome this challenge, we have measured the wavelength-modulated absorption (WMA) spectrum of 4H-SiC over a broader wavelength range (3500–3800 Å) and at a higher resolution (
doi_str_mv 10.1103/PhysRevB.102.205203
format Article
fullrecord <record><control><sourceid>proquest</sourceid><recordid>TN_cdi_proquest_journals_2470034361</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><sourcerecordid>2470034361</sourcerecordid><originalsourceid>FETCH-LOGICAL-p183t-fe3836d17ddd8ef159e2751180a7bb353cbe12f33f6be015dd3a9bf07329b50a3</originalsourceid><addsrcrecordid>eNpNj81KAzEUhYMoWGqfwM2AW6feJPOXpS1qhYLiz7okkzvOlGkyTjKtfRWf1pSKuLqHw-H7uIRcUphSCvzmud67F9zOphTYlEHKgJ-QEUsyEQuRidO_nMI5mTi3BgCagchBjMj3TBodOd8PpR96jLredtj7Bt111NXWWBPCYYJfZeOtiarG4L99Y6JkEb8282iD0oVGR2of7eQWWzQfvo43Vg-t9KGXytm-802AHICt3cUeN8Emj-baetsOm8B3JZoSL8hZJVuHk987Ju_3d2_zRbx8enic3y7jjhbcxxXygmea5lrrAiuaCmR5SmkBMleKp7xUSFnFeZUpBJpqzaVQFeScCZWC5GNydeSG3z8HdH61tkNvgnLFkhyAJzyj_Aej6nDG</addsrcrecordid><sourcetype>Aggregation Database</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype><pqid>2470034361</pqid></control><display><type>article</type><title>Band structure properties, phonons, and exciton fine structure in 4H-SiC measured by wavelength-modulated absorption and low-temperature photoluminescence</title><source>American Physical Society Journals</source><creator>Klahold, W M ; Choyke, W J ; Devaty, R P</creator><creatorcontrib>Klahold, W M ; Choyke, W J ; Devaty, R P</creatorcontrib><description>Owing to its hexagonal symmetry, indirect band gap, and relatively large unit cell, the electronic band structure of 4H-SiC is comprised of a complicated series of anisotropic valence and conduction band extrema even very near to the uppermost valence band maximum and lowest conduction band minimum. This has presented a difficult challenge to those experiments which have attempted to resolve the small energy separations between these band extrema. To overcome this challenge, we have measured the wavelength-modulated absorption (WMA) spectrum of 4H-SiC over a broader wavelength range (3500–3800 Å) and at a higher resolution (&lt;0.1 Å) than in previous work. By comparing these measurements with the low-temperature photoluminescence spectrum in ultrapure 4H-SiC, we have identified several features, which we attribute to a 56 ± 3 meV crystal-field splitting of the valence band maximum or a 136 ± 3 meV separation between the two lowest conduction band minima. We also show that the spin-orbit split-off valence band, which has been observed in previous measurements of 4H-SiC, contributes to nonparabolic dispersion near the valence band maximum, and this is responsible for several previously misidentified features in the WMA spectrum. Finally, we report the first experimental measurement of fine structure splittings in the free exciton ground state, which manifests as four small ( 0.7 ± 0.1 meV) splittings in the WMA spectrum due to mass anisotropy and electron-hole exchange interaction.</description><identifier>ISSN: 2469-9950</identifier><identifier>EISSN: 2469-9969</identifier><identifier>DOI: 10.1103/PhysRevB.102.205203</identifier><language>eng</language><publisher>College Park: American Physical Society</publisher><subject>Absorption ; Anisotropy ; Band structure of solids ; Conduction bands ; Electrons ; Excitons ; Fine structure ; Holes (electron deficiencies) ; Low temperature ; Photoluminescence ; Unit cell ; Valence band</subject><ispartof>Physical review. B, 2020-11, Vol.102 (20), p.205203</ispartof><rights>Copyright American Physical Society Nov 15, 2020</rights><lds50>peer_reviewed</lds50><woscitedreferencessubscribed>false</woscitedreferencessubscribed></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><link.rule.ids>314,780,784,27924,27925</link.rule.ids></links><search><creatorcontrib>Klahold, W M</creatorcontrib><creatorcontrib>Choyke, W J</creatorcontrib><creatorcontrib>Devaty, R P</creatorcontrib><title>Band structure properties, phonons, and exciton fine structure in 4H-SiC measured by wavelength-modulated absorption and low-temperature photoluminescence</title><title>Physical review. B</title><description>Owing to its hexagonal symmetry, indirect band gap, and relatively large unit cell, the electronic band structure of 4H-SiC is comprised of a complicated series of anisotropic valence and conduction band extrema even very near to the uppermost valence band maximum and lowest conduction band minimum. This has presented a difficult challenge to those experiments which have attempted to resolve the small energy separations between these band extrema. To overcome this challenge, we have measured the wavelength-modulated absorption (WMA) spectrum of 4H-SiC over a broader wavelength range (3500–3800 Å) and at a higher resolution (&lt;0.1 Å) than in previous work. By comparing these measurements with the low-temperature photoluminescence spectrum in ultrapure 4H-SiC, we have identified several features, which we attribute to a 56 ± 3 meV crystal-field splitting of the valence band maximum or a 136 ± 3 meV separation between the two lowest conduction band minima. We also show that the spin-orbit split-off valence band, which has been observed in previous measurements of 4H-SiC, contributes to nonparabolic dispersion near the valence band maximum, and this is responsible for several previously misidentified features in the WMA spectrum. Finally, we report the first experimental measurement of fine structure splittings in the free exciton ground state, which manifests as four small ( 0.7 ± 0.1 meV) splittings in the WMA spectrum due to mass anisotropy and electron-hole exchange interaction.</description><subject>Absorption</subject><subject>Anisotropy</subject><subject>Band structure of solids</subject><subject>Conduction bands</subject><subject>Electrons</subject><subject>Excitons</subject><subject>Fine structure</subject><subject>Holes (electron deficiencies)</subject><subject>Low temperature</subject><subject>Photoluminescence</subject><subject>Unit cell</subject><subject>Valence band</subject><issn>2469-9950</issn><issn>2469-9969</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2020</creationdate><recordtype>article</recordtype><recordid>eNpNj81KAzEUhYMoWGqfwM2AW6feJPOXpS1qhYLiz7okkzvOlGkyTjKtfRWf1pSKuLqHw-H7uIRcUphSCvzmud67F9zOphTYlEHKgJ-QEUsyEQuRidO_nMI5mTi3BgCagchBjMj3TBodOd8PpR96jLredtj7Bt111NXWWBPCYYJfZeOtiarG4L99Y6JkEb8282iD0oVGR2of7eQWWzQfvo43Vg-t9KGXytm-802AHICt3cUeN8Emj-baetsOm8B3JZoSL8hZJVuHk987Ju_3d2_zRbx8enic3y7jjhbcxxXygmea5lrrAiuaCmR5SmkBMleKp7xUSFnFeZUpBJpqzaVQFeScCZWC5GNydeSG3z8HdH61tkNvgnLFkhyAJzyj_Aej6nDG</recordid><startdate>20201123</startdate><enddate>20201123</enddate><creator>Klahold, W M</creator><creator>Choyke, W J</creator><creator>Devaty, R P</creator><general>American Physical Society</general><scope>7SR</scope><scope>7U5</scope><scope>8BQ</scope><scope>8FD</scope><scope>H8D</scope><scope>JG9</scope><scope>L7M</scope></search><sort><creationdate>20201123</creationdate><title>Band structure properties, phonons, and exciton fine structure in 4H-SiC measured by wavelength-modulated absorption and low-temperature photoluminescence</title><author>Klahold, W M ; Choyke, W J ; Devaty, R P</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-p183t-fe3836d17ddd8ef159e2751180a7bb353cbe12f33f6be015dd3a9bf07329b50a3</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>2020</creationdate><topic>Absorption</topic><topic>Anisotropy</topic><topic>Band structure of solids</topic><topic>Conduction bands</topic><topic>Electrons</topic><topic>Excitons</topic><topic>Fine structure</topic><topic>Holes (electron deficiencies)</topic><topic>Low temperature</topic><topic>Photoluminescence</topic><topic>Unit cell</topic><topic>Valence band</topic><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Klahold, W M</creatorcontrib><creatorcontrib>Choyke, W J</creatorcontrib><creatorcontrib>Devaty, R P</creatorcontrib><collection>Engineered Materials Abstracts</collection><collection>Solid State and Superconductivity Abstracts</collection><collection>METADEX</collection><collection>Technology Research Database</collection><collection>Aerospace Database</collection><collection>Materials Research Database</collection><collection>Advanced Technologies Database with Aerospace</collection><jtitle>Physical review. B</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>Klahold, W M</au><au>Choyke, W J</au><au>Devaty, R P</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Band structure properties, phonons, and exciton fine structure in 4H-SiC measured by wavelength-modulated absorption and low-temperature photoluminescence</atitle><jtitle>Physical review. B</jtitle><date>2020-11-23</date><risdate>2020</risdate><volume>102</volume><issue>20</issue><spage>205203</spage><pages>205203-</pages><issn>2469-9950</issn><eissn>2469-9969</eissn><abstract>Owing to its hexagonal symmetry, indirect band gap, and relatively large unit cell, the electronic band structure of 4H-SiC is comprised of a complicated series of anisotropic valence and conduction band extrema even very near to the uppermost valence band maximum and lowest conduction band minimum. This has presented a difficult challenge to those experiments which have attempted to resolve the small energy separations between these band extrema. To overcome this challenge, we have measured the wavelength-modulated absorption (WMA) spectrum of 4H-SiC over a broader wavelength range (3500–3800 Å) and at a higher resolution (&lt;0.1 Å) than in previous work. By comparing these measurements with the low-temperature photoluminescence spectrum in ultrapure 4H-SiC, we have identified several features, which we attribute to a 56 ± 3 meV crystal-field splitting of the valence band maximum or a 136 ± 3 meV separation between the two lowest conduction band minima. We also show that the spin-orbit split-off valence band, which has been observed in previous measurements of 4H-SiC, contributes to nonparabolic dispersion near the valence band maximum, and this is responsible for several previously misidentified features in the WMA spectrum. Finally, we report the first experimental measurement of fine structure splittings in the free exciton ground state, which manifests as four small ( 0.7 ± 0.1 meV) splittings in the WMA spectrum due to mass anisotropy and electron-hole exchange interaction.</abstract><cop>College Park</cop><pub>American Physical Society</pub><doi>10.1103/PhysRevB.102.205203</doi></addata></record>
fulltext fulltext
identifier ISSN: 2469-9950
ispartof Physical review. B, 2020-11, Vol.102 (20), p.205203
issn 2469-9950
2469-9969
language eng
recordid cdi_proquest_journals_2470034361
source American Physical Society Journals
subjects Absorption
Anisotropy
Band structure of solids
Conduction bands
Electrons
Excitons
Fine structure
Holes (electron deficiencies)
Low temperature
Photoluminescence
Unit cell
Valence band
title Band structure properties, phonons, and exciton fine structure in 4H-SiC measured by wavelength-modulated absorption and low-temperature photoluminescence
url https://sfx.bib-bvb.de/sfx_tum?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2024-12-28T23%3A27%3A48IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-proquest&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Band%20structure%20properties,%20phonons,%20and%20exciton%20fine%20structure%20in%204H-SiC%20measured%20by%20wavelength-modulated%20absorption%20and%20low-temperature%20photoluminescence&rft.jtitle=Physical%20review.%20B&rft.au=Klahold,%20W%20M&rft.date=2020-11-23&rft.volume=102&rft.issue=20&rft.spage=205203&rft.pages=205203-&rft.issn=2469-9950&rft.eissn=2469-9969&rft_id=info:doi/10.1103/PhysRevB.102.205203&rft_dat=%3Cproquest%3E2470034361%3C/proquest%3E%3Curl%3E%3C/url%3E&disable_directlink=true&sfx.directlink=off&sfx.report_link=0&rft_id=info:oai/&rft_pqid=2470034361&rft_id=info:pmid/&rfr_iscdi=true