Dielectric function of Cu(In, Ga)Se2-based polycrystalline materials
The dielectric functions of Cu(In, Ga)Se2(CIGS)-based polycrystalline layers with different Ga and Cu compositions have been determined by applying spectroscopic ellipsometry (SE) in a wide energy range of 0.7–6.5 eV. To suppress SE analysis errors induced by rough surface and compositional fluctuat...
Gespeichert in:
| Veröffentlicht in: | Journal of applied physics 2013-02, Vol.113 (6) |
|---|---|
| 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 | 6 |
| container_start_page | |
| container_title | Journal of applied physics |
| container_volume | 113 |
| creator | Minoura, Shota Kodera, Keita Maekawa, Takuji Miyazaki, Kenichi Niki, Shigeru Fujiwara, Hiroyuki |
| description | The dielectric functions of Cu(In, Ga)Se2(CIGS)-based polycrystalline layers with different Ga and Cu compositions have been determined by applying spectroscopic ellipsometry (SE) in a wide energy range of 0.7–6.5 eV. To suppress SE analysis errors induced by rough surface and compositional fluctuation, quite thin CIGS layers ( 1, on the other hand, the free-carrier absorption increases drastically due to the formation of a semi-metallic CuxSe phase with a constant band gap in the CIGS component. In this study, by using a standard critical-point line-shape analysis, the critical point energies of the CIGS-based layers with different Ga and Cu compositions have been determined. Based on these results, we will discuss the optical transitions in CIGS-based polycrystalline materials. |
| doi_str_mv | 10.1063/1.4790174 |
| format | Article |
| fullrecord | <record><control><sourceid>proquest_cross</sourceid><recordid>TN_cdi_proquest_miscellaneous_1671493538</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><sourcerecordid>1671493538</sourcerecordid><originalsourceid>FETCH-LOGICAL-c328t-21b88e0964a78aaa515ed84c039ed3e3a280d0dedb0ef998493b15b15a3775d13</originalsourceid><addsrcrecordid>eNotkEFLwzAYhoMoOKcH_0GPG9j5fU2zJEfZdA4GHtRzSZOvEMnambSH_nsrG7zwXN73PTyMPSKsENb8GVel1ICyvGIzBKVzKQRcsxlAgbnSUt-yu5R-ABAV1zO23XoKZPvobdYMre1912Zdk22Gxb59ynZm-UlFXptELjt1YbRxTL0JwbeUHU1P0ZuQ7tlNM4EeLpyz77fXr817fvjY7Tcvh9zyQvV5gbVSBHpdGqmMMQIFOVVa4JocJ24KBQ4cuRqo0VqVmtcophgupXDI52xx_j3F7neg1FdHnyyFYFrqhlThWuI0ElxN1eW5amOXUqSmOkV_NHGsEKp_UxVWF1P8DwEzWYM</addsrcrecordid><sourcetype>Aggregation Database</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype><pqid>1671493538</pqid></control><display><type>article</type><title>Dielectric function of Cu(In, Ga)Se2-based polycrystalline materials</title><source>AIP Journals Complete</source><source>AIP Digital Archive</source><source>Alma/SFX Local Collection</source><creator>Minoura, Shota ; Kodera, Keita ; Maekawa, Takuji ; Miyazaki, Kenichi ; Niki, Shigeru ; Fujiwara, Hiroyuki</creator><creatorcontrib>Minoura, Shota ; Kodera, Keita ; Maekawa, Takuji ; Miyazaki, Kenichi ; Niki, Shigeru ; Fujiwara, Hiroyuki</creatorcontrib><description>The dielectric functions of Cu(In, Ga)Se2(CIGS)-based polycrystalline layers with different Ga and Cu compositions have been determined by applying spectroscopic ellipsometry (SE) in a wide energy range of 0.7–6.5 eV. To suppress SE analysis errors induced by rough surface and compositional fluctuation, quite thin CIGS layers (<60 nm) with high uniformity toward the growth direction have been characterized using a self-consistent SE analysis method. We find that the optical model used in many previous studies is oversimplified particularly for the roughness/overlayer contribution, and all the artifacts arising from the simplified analysis have been removed almost completely in our approach. The CIGS dielectric functions with the variation of the Ga composition [x = Ga/(In + Ga)] revealed that (i) the whole CIGS dielectric function shifts toward higher energies with x, (ii) the band gap increases linearly with x without the band-gap bowing effect, and (iii) the overall absorption coefficients are significantly smaller than those reported earlier. Furthermore, the reduction of the Cu composition [y = Cu/(In + Ga)] leads to (i) the linear increase in the band-edge transition energy and (ii) the decrease in the absorption coefficient, due to the smaller interaction of the Cu 3d orbitals near the valence band maximum in the Cu-deficient layers. When y > 1, on the other hand, the free-carrier absorption increases drastically due to the formation of a semi-metallic CuxSe phase with a constant band gap in the CIGS component. In this study, by using a standard critical-point line-shape analysis, the critical point energies of the CIGS-based layers with different Ga and Cu compositions have been determined. Based on these results, we will discuss the optical transitions in CIGS-based polycrystalline materials.</description><identifier>ISSN: 0021-8979</identifier><identifier>EISSN: 1089-7550</identifier><identifier>DOI: 10.1063/1.4790174</identifier><language>eng</language><subject>Absorption coefficient ; CIGS ; Copper ; COPPER SELENIDE ; CRYSTAL STRUCTURE ; Dielectrics ; Gallium ; INSULATION (ELECTRICAL) ; MATHEMATICAL ANALYSIS ; Mathematical models ; Optical transition ; Orbitals ; Roughness ; VALENCE</subject><ispartof>Journal of applied physics, 2013-02, Vol.113 (6)</ispartof><lds50>peer_reviewed</lds50><woscitedreferencessubscribed>false</woscitedreferencessubscribed><citedby>FETCH-LOGICAL-c328t-21b88e0964a78aaa515ed84c039ed3e3a280d0dedb0ef998493b15b15a3775d13</citedby><cites>FETCH-LOGICAL-c328t-21b88e0964a78aaa515ed84c039ed3e3a280d0dedb0ef998493b15b15a3775d13</cites></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>Minoura, Shota</creatorcontrib><creatorcontrib>Kodera, Keita</creatorcontrib><creatorcontrib>Maekawa, Takuji</creatorcontrib><creatorcontrib>Miyazaki, Kenichi</creatorcontrib><creatorcontrib>Niki, Shigeru</creatorcontrib><creatorcontrib>Fujiwara, Hiroyuki</creatorcontrib><title>Dielectric function of Cu(In, Ga)Se2-based polycrystalline materials</title><title>Journal of applied physics</title><description>The dielectric functions of Cu(In, Ga)Se2(CIGS)-based polycrystalline layers with different Ga and Cu compositions have been determined by applying spectroscopic ellipsometry (SE) in a wide energy range of 0.7–6.5 eV. To suppress SE analysis errors induced by rough surface and compositional fluctuation, quite thin CIGS layers (<60 nm) with high uniformity toward the growth direction have been characterized using a self-consistent SE analysis method. We find that the optical model used in many previous studies is oversimplified particularly for the roughness/overlayer contribution, and all the artifacts arising from the simplified analysis have been removed almost completely in our approach. The CIGS dielectric functions with the variation of the Ga composition [x = Ga/(In + Ga)] revealed that (i) the whole CIGS dielectric function shifts toward higher energies with x, (ii) the band gap increases linearly with x without the band-gap bowing effect, and (iii) the overall absorption coefficients are significantly smaller than those reported earlier. Furthermore, the reduction of the Cu composition [y = Cu/(In + Ga)] leads to (i) the linear increase in the band-edge transition energy and (ii) the decrease in the absorption coefficient, due to the smaller interaction of the Cu 3d orbitals near the valence band maximum in the Cu-deficient layers. When y > 1, on the other hand, the free-carrier absorption increases drastically due to the formation of a semi-metallic CuxSe phase with a constant band gap in the CIGS component. In this study, by using a standard critical-point line-shape analysis, the critical point energies of the CIGS-based layers with different Ga and Cu compositions have been determined. Based on these results, we will discuss the optical transitions in CIGS-based polycrystalline materials.</description><subject>Absorption coefficient</subject><subject>CIGS</subject><subject>Copper</subject><subject>COPPER SELENIDE</subject><subject>CRYSTAL STRUCTURE</subject><subject>Dielectrics</subject><subject>Gallium</subject><subject>INSULATION (ELECTRICAL)</subject><subject>MATHEMATICAL ANALYSIS</subject><subject>Mathematical models</subject><subject>Optical transition</subject><subject>Orbitals</subject><subject>Roughness</subject><subject>VALENCE</subject><issn>0021-8979</issn><issn>1089-7550</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2013</creationdate><recordtype>article</recordtype><recordid>eNotkEFLwzAYhoMoOKcH_0GPG9j5fU2zJEfZdA4GHtRzSZOvEMnambSH_nsrG7zwXN73PTyMPSKsENb8GVel1ICyvGIzBKVzKQRcsxlAgbnSUt-yu5R-ABAV1zO23XoKZPvobdYMre1912Zdk22Gxb59ynZm-UlFXptELjt1YbRxTL0JwbeUHU1P0ZuQ7tlNM4EeLpyz77fXr817fvjY7Tcvh9zyQvV5gbVSBHpdGqmMMQIFOVVa4JocJ24KBQ4cuRqo0VqVmtcophgupXDI52xx_j3F7neg1FdHnyyFYFrqhlThWuI0ElxN1eW5amOXUqSmOkV_NHGsEKp_UxVWF1P8DwEzWYM</recordid><startdate>20130214</startdate><enddate>20130214</enddate><creator>Minoura, Shota</creator><creator>Kodera, Keita</creator><creator>Maekawa, Takuji</creator><creator>Miyazaki, Kenichi</creator><creator>Niki, Shigeru</creator><creator>Fujiwara, Hiroyuki</creator><scope>AAYXX</scope><scope>CITATION</scope><scope>7QQ</scope><scope>7U5</scope><scope>8FD</scope><scope>H8D</scope><scope>H8G</scope><scope>JG9</scope><scope>L7M</scope></search><sort><creationdate>20130214</creationdate><title>Dielectric function of Cu(In, Ga)Se2-based polycrystalline materials</title><author>Minoura, Shota ; Kodera, Keita ; Maekawa, Takuji ; Miyazaki, Kenichi ; Niki, Shigeru ; Fujiwara, Hiroyuki</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-c328t-21b88e0964a78aaa515ed84c039ed3e3a280d0dedb0ef998493b15b15a3775d13</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>2013</creationdate><topic>Absorption coefficient</topic><topic>CIGS</topic><topic>Copper</topic><topic>COPPER SELENIDE</topic><topic>CRYSTAL STRUCTURE</topic><topic>Dielectrics</topic><topic>Gallium</topic><topic>INSULATION (ELECTRICAL)</topic><topic>MATHEMATICAL ANALYSIS</topic><topic>Mathematical models</topic><topic>Optical transition</topic><topic>Orbitals</topic><topic>Roughness</topic><topic>VALENCE</topic><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Minoura, Shota</creatorcontrib><creatorcontrib>Kodera, Keita</creatorcontrib><creatorcontrib>Maekawa, Takuji</creatorcontrib><creatorcontrib>Miyazaki, Kenichi</creatorcontrib><creatorcontrib>Niki, Shigeru</creatorcontrib><creatorcontrib>Fujiwara, Hiroyuki</creatorcontrib><collection>CrossRef</collection><collection>Ceramic Abstracts</collection><collection>Solid State and Superconductivity Abstracts</collection><collection>Technology Research Database</collection><collection>Aerospace Database</collection><collection>Copper Technical Reference Library</collection><collection>Materials Research 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>Minoura, Shota</au><au>Kodera, Keita</au><au>Maekawa, Takuji</au><au>Miyazaki, Kenichi</au><au>Niki, Shigeru</au><au>Fujiwara, Hiroyuki</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Dielectric function of Cu(In, Ga)Se2-based polycrystalline materials</atitle><jtitle>Journal of applied physics</jtitle><date>2013-02-14</date><risdate>2013</risdate><volume>113</volume><issue>6</issue><issn>0021-8979</issn><eissn>1089-7550</eissn><abstract>The dielectric functions of Cu(In, Ga)Se2(CIGS)-based polycrystalline layers with different Ga and Cu compositions have been determined by applying spectroscopic ellipsometry (SE) in a wide energy range of 0.7–6.5 eV. To suppress SE analysis errors induced by rough surface and compositional fluctuation, quite thin CIGS layers (<60 nm) with high uniformity toward the growth direction have been characterized using a self-consistent SE analysis method. We find that the optical model used in many previous studies is oversimplified particularly for the roughness/overlayer contribution, and all the artifacts arising from the simplified analysis have been removed almost completely in our approach. The CIGS dielectric functions with the variation of the Ga composition [x = Ga/(In + Ga)] revealed that (i) the whole CIGS dielectric function shifts toward higher energies with x, (ii) the band gap increases linearly with x without the band-gap bowing effect, and (iii) the overall absorption coefficients are significantly smaller than those reported earlier. Furthermore, the reduction of the Cu composition [y = Cu/(In + Ga)] leads to (i) the linear increase in the band-edge transition energy and (ii) the decrease in the absorption coefficient, due to the smaller interaction of the Cu 3d orbitals near the valence band maximum in the Cu-deficient layers. When y > 1, on the other hand, the free-carrier absorption increases drastically due to the formation of a semi-metallic CuxSe phase with a constant band gap in the CIGS component. In this study, by using a standard critical-point line-shape analysis, the critical point energies of the CIGS-based layers with different Ga and Cu compositions have been determined. Based on these results, we will discuss the optical transitions in CIGS-based polycrystalline materials.</abstract><doi>10.1063/1.4790174</doi></addata></record> |
| fulltext | fulltext |
| identifier | ISSN: 0021-8979 |
| ispartof | Journal of applied physics, 2013-02, Vol.113 (6) |
| issn | 0021-8979 1089-7550 |
| language | eng |
| recordid | cdi_proquest_miscellaneous_1671493538 |
| source | AIP Journals Complete; AIP Digital Archive; Alma/SFX Local Collection |
| subjects | Absorption coefficient CIGS Copper COPPER SELENIDE CRYSTAL STRUCTURE Dielectrics Gallium INSULATION (ELECTRICAL) MATHEMATICAL ANALYSIS Mathematical models Optical transition Orbitals Roughness VALENCE |
| title | Dielectric function of Cu(In, Ga)Se2-based polycrystalline materials |
| url | https://sfx.bib-bvb.de/sfx_tum?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2025-01-06T03%3A13%3A24IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-proquest_cross&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Dielectric%20function%20of%20Cu(In,%20Ga)Se2-based%20polycrystalline%20materials&rft.jtitle=Journal%20of%20applied%20physics&rft.au=Minoura,%20Shota&rft.date=2013-02-14&rft.volume=113&rft.issue=6&rft.issn=0021-8979&rft.eissn=1089-7550&rft_id=info:doi/10.1063/1.4790174&rft_dat=%3Cproquest_cross%3E1671493538%3C/proquest_cross%3E%3Curl%3E%3C/url%3E&disable_directlink=true&sfx.directlink=off&sfx.report_link=0&rft_id=info:oai/&rft_pqid=1671493538&rft_id=info:pmid/&rfr_iscdi=true |