Origin of Photocarrier Losses in Iron Pyrite (FeS2) Nanocubes
Iron pyrite has received significant attention due to its high optical absorption. However, the loss of open circuit voltage (Voc) prevents its further application in photovoltaics. Herein, we have studied the photophysics of pyrite by ultrafast laser spectroscopy to understand fundamental limitatio...
| Main Authors: | , , , , , , , , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
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2017
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| Online Access: | https://hdl.handle.net/10356/86284 http://hdl.handle.net/10220/43983 |
| _version_ | 1824457079618797568 |
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| author | Shukla, Sudhanshu Xing, Guichuan Ge, Hu Prabhakar, Rajiv Ramanujam Mathew, Sinu Su, Zhenghua Nalla, Venkatram Venkatesan, Thirumalai Mathews, Nripan Sritharan, Thirumany Sum, Tze Chien Xiong, Qihua |
| author2 | School of Electrical and Electronic Engineering |
| author_facet | School of Electrical and Electronic Engineering Shukla, Sudhanshu Xing, Guichuan Ge, Hu Prabhakar, Rajiv Ramanujam Mathew, Sinu Su, Zhenghua Nalla, Venkatram Venkatesan, Thirumalai Mathews, Nripan Sritharan, Thirumany Sum, Tze Chien Xiong, Qihua |
| author_sort | Shukla, Sudhanshu |
| collection | NTU |
| description | Iron pyrite has received significant attention due to its high optical absorption. However, the loss of open circuit voltage (Voc) prevents its further application in photovoltaics. Herein, we have studied the photophysics of pyrite by ultrafast laser spectroscopy to understand fundamental limitation of low Voc by quantifying photocarrier losses in high quality, stoichiometric, and phase pure {100} faceted pyrite nanocubes. We found that fast carrier localization of photoexcited carriers to indirect band edge and shallow trap states is responsible for major carrier loss. Slow relaxation component reflects high density of defects within the band gap which is consistent with the observed Mott-variable range hopping (VRH) conduction from transport measurements. Magnetic measurements strikingly show the magnetic ordering associated with phase inhomogeneity, such as FeS2−δ (0 ≤ δ ≤ 1). This implies that improvement of iron pyrite solar cell performance lies in mitigating the intrinsic defects (such as sulfur vacancies) by blocking the fast carrier localization process. Photocarrier generation and relaxation model is presented by comprehensive analysis. Our results provide insight into possible defects that induce midgap states and facilitate rapid carrier relaxation before collection. |
| first_indexed | 2025-02-19T04:04:18Z |
| format | Journal Article |
| id | ntu-10356/86284 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2025-02-19T04:04:18Z |
| publishDate | 2017 |
| record_format | dspace |
| spelling | ntu-10356/862842021-01-14T06:19:52Z Origin of Photocarrier Losses in Iron Pyrite (FeS2) Nanocubes Shukla, Sudhanshu Xing, Guichuan Ge, Hu Prabhakar, Rajiv Ramanujam Mathew, Sinu Su, Zhenghua Nalla, Venkatram Venkatesan, Thirumalai Mathews, Nripan Sritharan, Thirumany Sum, Tze Chien Xiong, Qihua School of Electrical and Electronic Engineering School of Materials Science and Engineering School of Physical and Mathematical Sciences Interdisciplinary Graduate School (IGS) Centre for Disruptive Photonic Technologies (CDPT) Nanoelectronics Centre of Excellence Energy Research Institute @ NTU (ERI@N) Variable range hopping Transient absorption Iron pyrite has received significant attention due to its high optical absorption. However, the loss of open circuit voltage (Voc) prevents its further application in photovoltaics. Herein, we have studied the photophysics of pyrite by ultrafast laser spectroscopy to understand fundamental limitation of low Voc by quantifying photocarrier losses in high quality, stoichiometric, and phase pure {100} faceted pyrite nanocubes. We found that fast carrier localization of photoexcited carriers to indirect band edge and shallow trap states is responsible for major carrier loss. Slow relaxation component reflects high density of defects within the band gap which is consistent with the observed Mott-variable range hopping (VRH) conduction from transport measurements. Magnetic measurements strikingly show the magnetic ordering associated with phase inhomogeneity, such as FeS2−δ (0 ≤ δ ≤ 1). This implies that improvement of iron pyrite solar cell performance lies in mitigating the intrinsic defects (such as sulfur vacancies) by blocking the fast carrier localization process. Photocarrier generation and relaxation model is presented by comprehensive analysis. Our results provide insight into possible defects that induce midgap states and facilitate rapid carrier relaxation before collection. NRF (Natl Research Foundation, S’pore) MOE (Min. of Education, S’pore) 2017-11-01T09:06:12Z 2019-12-06T16:19:36Z 2017-11-01T09:06:12Z 2019-12-06T16:19:36Z 2016 Journal Article Shukla, S., Xing, G., Ge, H., Prabhakar, R. R., Mathew, S., Su, Z., et al. (2016). Origin of Photocarrier Losses in Iron Pyrite (FeS2) Nanocubes. ACS Nano, 10(4), 4431-4440. 1936-0851 https://hdl.handle.net/10356/86284 http://hdl.handle.net/10220/43983 10.1021/acsnano.6b00065 en ACS Nano © 2016 American Chemical Society. |
| spellingShingle | Variable range hopping Transient absorption Shukla, Sudhanshu Xing, Guichuan Ge, Hu Prabhakar, Rajiv Ramanujam Mathew, Sinu Su, Zhenghua Nalla, Venkatram Venkatesan, Thirumalai Mathews, Nripan Sritharan, Thirumany Sum, Tze Chien Xiong, Qihua Origin of Photocarrier Losses in Iron Pyrite (FeS2) Nanocubes |
| title | Origin of Photocarrier Losses in Iron Pyrite (FeS2) Nanocubes |
| title_full | Origin of Photocarrier Losses in Iron Pyrite (FeS2) Nanocubes |
| title_fullStr | Origin of Photocarrier Losses in Iron Pyrite (FeS2) Nanocubes |
| title_full_unstemmed | Origin of Photocarrier Losses in Iron Pyrite (FeS2) Nanocubes |
| title_short | Origin of Photocarrier Losses in Iron Pyrite (FeS2) Nanocubes |
| title_sort | origin of photocarrier losses in iron pyrite fes2 nanocubes |
| topic | Variable range hopping Transient absorption |
| url | https://hdl.handle.net/10356/86284 http://hdl.handle.net/10220/43983 |
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