Picosecond carrier recombination dynamics in chalcogen-hyperdoped silicon
Intermediate-band materials have the potential to be highly efficient solar cells and can be fabricated by incorporating ultrahigh concentrations of deep-level dopants. Direct measurements of the ultrafast carrier recombination processes under supersaturated dopant concentrations have not been previ...
| Những tác giả chính: | , , , , , , , , |
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| Tác giả khác: | |
| Định dạng: | Bài viết |
| Ngôn ngữ: | en_US |
| Được phát hành: |
American Institute of Physics (AIP)
2015
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| Truy cập trực tuyến: | http://hdl.handle.net/1721.1/97242 https://orcid.org/0000-0001-8345-4937 |
| Tóm tắt: | Intermediate-band materials have the potential to be highly efficient solar cells and can be fabricated by incorporating ultrahigh concentrations of deep-level dopants. Direct measurements of the ultrafast carrier recombination processes under supersaturated dopant concentrations have not been previously conducted. Here, we use optical-pump/terahertz-probe measurements to study carrier recombination dynamics of chalcogen-hyperdoped silicon with sub-picosecond resolution. The recombination dynamics is described by two exponential decay time scales: a fast decay time scale ranges between 1 and 200 ps followed by a slow decay on the order of 1 ns. In contrast to the prior theoretical predictions, we find that the carrier lifetime decreases with increasing dopant concentration up to and above the insulator-to-metal transition. Evaluating the material's figure of merit reveals an optimum doping concentration for maximizing performance. |
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