Stable and High Piezoelectric Output of GaN Nanowire-Based Lead-Free Piezoelectric Nanogenerator by Suppression of Internal Screening
A piezoelectric nanogenerator (PNG) that is based on c-axis GaN nanowires is fabricated on flexible substrate. In this regard, c-axis GaN nanowires were grown on GaN substrate using the vapor-liquid-solid (VLS) technique by metal organic chemical vapor deposition. Further, Polydimethylsiloxane (PDMS...
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MDPI AG
2018-06-01
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| Series: | Nanomaterials |
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| Online Access: | http://www.mdpi.com/2079-4991/8/6/437 |
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| author | Muhammad Ali Johar Mostafa Afifi Hassan Aadil Waseem Jun-Seok Ha June Key Lee Sang-Wan Ryu |
| author_facet | Muhammad Ali Johar Mostafa Afifi Hassan Aadil Waseem Jun-Seok Ha June Key Lee Sang-Wan Ryu |
| author_sort | Muhammad Ali Johar |
| collection | DOAJ |
| description | A piezoelectric nanogenerator (PNG) that is based on c-axis GaN nanowires is fabricated on flexible substrate. In this regard, c-axis GaN nanowires were grown on GaN substrate using the vapor-liquid-solid (VLS) technique by metal organic chemical vapor deposition. Further, Polydimethylsiloxane (PDMS) was coated on nanowire-arrays then PDMS matrix embedded with GaN nanowire-arrays was transferred on Si-rubber substrate. The piezoelectric performance of nanowire-based flexible PNG was measured, while the device was actuated using a cyclic stretching-releasing agitation mechanism that was driven by a linear motor. The piezoelectric output was measured as a function of actuation frequency ranging from 1 Hz to 10 Hz and a linear tendency was observed for piezoelectric output current, while the output voltages remained constant. A maximum of piezoelectric open circuit voltages and short circuit current were measured 15.4 V and 85.6 nA, respectively. In order to evaluate the feasibility of our flexible PNG for real application, a long term stability test was performed for 20,000 cycles and the device performance was degraded by less than 18%. The underlying reason for the high piezoelectric output was attributed to the reduced free carriers inside nanowires due to surface Fermi-level pinning and insulating metal-dielectric-semiconductor interface, respectively; the former reduced the free carrier screening radially while latter reduced longitudinally. The flexibility and the high aspect ratio of GaN nanowire were the responsible factors for higher stability. Such higher piezoelectric output and the novel design make our device more promising for the diverse range of real applications. |
| first_indexed | 2024-12-11T18:26:50Z |
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| id | doaj.art-87de10180d7c411184e41fb20729df19 |
| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-12-11T18:26:50Z |
| publishDate | 2018-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nanomaterials |
| spelling | doaj.art-87de10180d7c411184e41fb20729df192022-12-22T00:55:03ZengMDPI AGNanomaterials2079-49912018-06-018643710.3390/nano8060437nano8060437Stable and High Piezoelectric Output of GaN Nanowire-Based Lead-Free Piezoelectric Nanogenerator by Suppression of Internal ScreeningMuhammad Ali Johar0Mostafa Afifi Hassan1Aadil Waseem2Jun-Seok Ha3June Key Lee4Sang-Wan Ryu5Department of Physics, Chonnam National University, Gwangju 61186, KoreaDepartment of Physics, Chonnam National University, Gwangju 61186, KoreaDepartment of Physics, Chonnam National University, Gwangju 61186, KoreaOptoelectronics Convergence Research Center, Chonnam National University, Gwangju 61186, KoreaOptoelectronics Convergence Research Center, Chonnam National University, Gwangju 61186, KoreaDepartment of Physics, Chonnam National University, Gwangju 61186, KoreaA piezoelectric nanogenerator (PNG) that is based on c-axis GaN nanowires is fabricated on flexible substrate. In this regard, c-axis GaN nanowires were grown on GaN substrate using the vapor-liquid-solid (VLS) technique by metal organic chemical vapor deposition. Further, Polydimethylsiloxane (PDMS) was coated on nanowire-arrays then PDMS matrix embedded with GaN nanowire-arrays was transferred on Si-rubber substrate. The piezoelectric performance of nanowire-based flexible PNG was measured, while the device was actuated using a cyclic stretching-releasing agitation mechanism that was driven by a linear motor. The piezoelectric output was measured as a function of actuation frequency ranging from 1 Hz to 10 Hz and a linear tendency was observed for piezoelectric output current, while the output voltages remained constant. A maximum of piezoelectric open circuit voltages and short circuit current were measured 15.4 V and 85.6 nA, respectively. In order to evaluate the feasibility of our flexible PNG for real application, a long term stability test was performed for 20,000 cycles and the device performance was degraded by less than 18%. The underlying reason for the high piezoelectric output was attributed to the reduced free carriers inside nanowires due to surface Fermi-level pinning and insulating metal-dielectric-semiconductor interface, respectively; the former reduced the free carrier screening radially while latter reduced longitudinally. The flexibility and the high aspect ratio of GaN nanowire were the responsible factors for higher stability. Such higher piezoelectric output and the novel design make our device more promising for the diverse range of real applications.http://www.mdpi.com/2079-4991/8/6/437GaN nanowiresnanogeneratorpiezoelectricityflexible electronicsfree-carrier screening |
| spellingShingle | Muhammad Ali Johar Mostafa Afifi Hassan Aadil Waseem Jun-Seok Ha June Key Lee Sang-Wan Ryu Stable and High Piezoelectric Output of GaN Nanowire-Based Lead-Free Piezoelectric Nanogenerator by Suppression of Internal Screening Nanomaterials GaN nanowires nanogenerator piezoelectricity flexible electronics free-carrier screening |
| title | Stable and High Piezoelectric Output of GaN Nanowire-Based Lead-Free Piezoelectric Nanogenerator by Suppression of Internal Screening |
| title_full | Stable and High Piezoelectric Output of GaN Nanowire-Based Lead-Free Piezoelectric Nanogenerator by Suppression of Internal Screening |
| title_fullStr | Stable and High Piezoelectric Output of GaN Nanowire-Based Lead-Free Piezoelectric Nanogenerator by Suppression of Internal Screening |
| title_full_unstemmed | Stable and High Piezoelectric Output of GaN Nanowire-Based Lead-Free Piezoelectric Nanogenerator by Suppression of Internal Screening |
| title_short | Stable and High Piezoelectric Output of GaN Nanowire-Based Lead-Free Piezoelectric Nanogenerator by Suppression of Internal Screening |
| title_sort | stable and high piezoelectric output of gan nanowire based lead free piezoelectric nanogenerator by suppression of internal screening |
| topic | GaN nanowires nanogenerator piezoelectricity flexible electronics free-carrier screening |
| url | http://www.mdpi.com/2079-4991/8/6/437 |
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