Thermoelectric properties of In-rich InGaN and InN/InGaN superlattices
The thermoelectric properties of n-type InGaN alloys with high In-content and InN/InGaN thin film superlattices (SL) grown by molecular beam epitaxy are investigated. Room-temperature measurements of the thermoelectric properties reveal that an increasing Ga-content in ternary InGaN alloys (0 < x...
| Hlavní autoři: | , , , , , , , , |
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| Médium: | Článek |
| Jazyk: | English |
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AIP Publishing LLC
2016-04-01
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| Edice: | AIP Advances |
| On-line přístup: | http://dx.doi.org/10.1063/1.4948446 |
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| author | James (Zi-Jian) Ju Bo Sun Georg Haunschild Bernhard Loitsch Benedikt Stoib Martin S. Brandt Martin Stutzmann Yee Kan Koh Gregor Koblmüller |
| author_facet | James (Zi-Jian) Ju Bo Sun Georg Haunschild Bernhard Loitsch Benedikt Stoib Martin S. Brandt Martin Stutzmann Yee Kan Koh Gregor Koblmüller |
| author_sort | James (Zi-Jian) Ju |
| collection | DOAJ |
| description | The thermoelectric properties of n-type InGaN alloys with high In-content and InN/InGaN thin film superlattices (SL) grown by molecular beam epitaxy are investigated. Room-temperature measurements of the thermoelectric properties reveal that an increasing Ga-content in ternary InGaN alloys (0 < x(Ga) < 0.2) yields a more than 10-fold reduction in thermal conductivity (κ) without deteriorating electrical conductivity (σ), while the Seebeck coefficient (S) increases slightly due to a widening band gap compared to binary InN. Employing InN/InGaN SLs (x(Ga) = 0.1) with different periods, we demonstrate that confinement effects strongly enhance electron mobility with values as high as ∼820 cm2/V s at an electron density ne of ∼5×1019 cm−3, leading to an exceptionally high σ of ∼5400 (Ωcm)−1. Simultaneously, in very short-period SL structures S becomes decoupled from ne, κ is further reduced below the alloy limit (κ < 9 W/m-K), and the power factor increases to 2.5×10−4 W/m-K2 by more than a factor of 5 as compared to In-rich InGaN alloys. These findings demonstrate that quantum confinement in group-III nitride-based superlattices facilitates improvements of thermoelectric properties over bulk-like ternary nitride alloys. |
| first_indexed | 2024-04-12T03:19:26Z |
| format | Article |
| id | doaj.art-226b6f07901b4e678bcbf1916e7ad2dc |
| institution | Directory Open Access Journal |
| issn | 2158-3226 |
| language | English |
| last_indexed | 2024-04-12T03:19:26Z |
| publishDate | 2016-04-01 |
| publisher | AIP Publishing LLC |
| record_format | Article |
| series | AIP Advances |
| spelling | doaj.art-226b6f07901b4e678bcbf1916e7ad2dc2022-12-22T03:49:57ZengAIP Publishing LLCAIP Advances2158-32262016-04-0164045216045216-910.1063/1.4948446066604ADVThermoelectric properties of In-rich InGaN and InN/InGaN superlatticesJames (Zi-Jian) Ju0Bo Sun1Georg Haunschild2Bernhard Loitsch3Benedikt Stoib4Martin S. Brandt5Martin Stutzmann6Yee Kan Koh7Gregor Koblmüller8Walter Schottky Institut, Physik Department, TU München, 85748 Garching, GermanyDepartment of Mechanical Engineering, National University of Singapore, 117576, SingaporeWalter Schottky Institut, Physik Department, TU München, 85748 Garching, GermanyWalter Schottky Institut, Physik Department, TU München, 85748 Garching, GermanyWalter Schottky Institut, Physik Department, TU München, 85748 Garching, GermanyWalter Schottky Institut, Physik Department, TU München, 85748 Garching, GermanyWalter Schottky Institut, Physik Department, TU München, 85748 Garching, GermanyDepartment of Mechanical Engineering, National University of Singapore, 117576, SingaporeWalter Schottky Institut, Physik Department, TU München, 85748 Garching, GermanyThe thermoelectric properties of n-type InGaN alloys with high In-content and InN/InGaN thin film superlattices (SL) grown by molecular beam epitaxy are investigated. Room-temperature measurements of the thermoelectric properties reveal that an increasing Ga-content in ternary InGaN alloys (0 < x(Ga) < 0.2) yields a more than 10-fold reduction in thermal conductivity (κ) without deteriorating electrical conductivity (σ), while the Seebeck coefficient (S) increases slightly due to a widening band gap compared to binary InN. Employing InN/InGaN SLs (x(Ga) = 0.1) with different periods, we demonstrate that confinement effects strongly enhance electron mobility with values as high as ∼820 cm2/V s at an electron density ne of ∼5×1019 cm−3, leading to an exceptionally high σ of ∼5400 (Ωcm)−1. Simultaneously, in very short-period SL structures S becomes decoupled from ne, κ is further reduced below the alloy limit (κ < 9 W/m-K), and the power factor increases to 2.5×10−4 W/m-K2 by more than a factor of 5 as compared to In-rich InGaN alloys. These findings demonstrate that quantum confinement in group-III nitride-based superlattices facilitates improvements of thermoelectric properties over bulk-like ternary nitride alloys.http://dx.doi.org/10.1063/1.4948446 |
| spellingShingle | James (Zi-Jian) Ju Bo Sun Georg Haunschild Bernhard Loitsch Benedikt Stoib Martin S. Brandt Martin Stutzmann Yee Kan Koh Gregor Koblmüller Thermoelectric properties of In-rich InGaN and InN/InGaN superlattices AIP Advances |
| title | Thermoelectric properties of In-rich InGaN and InN/InGaN superlattices |
| title_full | Thermoelectric properties of In-rich InGaN and InN/InGaN superlattices |
| title_fullStr | Thermoelectric properties of In-rich InGaN and InN/InGaN superlattices |
| title_full_unstemmed | Thermoelectric properties of In-rich InGaN and InN/InGaN superlattices |
| title_short | Thermoelectric properties of In-rich InGaN and InN/InGaN superlattices |
| title_sort | thermoelectric properties of in rich ingan and inn ingan superlattices |
| url | http://dx.doi.org/10.1063/1.4948446 |
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