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Picosecond carrier recombination dynamics in chalcogen-hyperdoped silicon
- Source :
- Other univ. web domain
- Publication Year :
- 2015
-
Abstract
- 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.<br />Center for Clean Water and Clean Energy at MIT and KFUPM<br />National Science Foundation (U.S.) (Grant Contract ECCS-1102050)<br />National Science Foundation (U.S.) (United States. Dept. of Energy Contract EEC-1041895)
Details
- Database :
- OAIster
- Journal :
- Other univ. web domain
- Notes :
- application/pdf, en_US
- Publication Type :
- Electronic Resource
- Accession number :
- edsoai.on1141889230
- Document Type :
- Electronic Resource