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Abstract Tellurium‐hyperdoped silicon (Si:Te) shows significant promise as an intermediate band material candidate for highly efficient solar cells and photodetectors. Time‐resolved THz spectroscopy (TRTS) is used to study the excited carrier dynamics of Si hyperdoped with 0.5, 1, and 2%. The two photoexcitation wavelengths enable us to understand the temperature‐dependent carrier transport in the hyperdoped region in comparison with the Si region. Temperature significantly influences the magnitude of transient conductivity and decay time when photoexcited by light with a wavelength of 400 nm. Due to the differential mobilities in the Si and hyperdoped regions, such dependence is absent under 266‐nm excitation. Consistent with the literature, the charge‐carrier lifetime decreases with increasing dopant concentration. It is found that the photoconductivity becomes less temperature‐dependent as the dopant concentration increases. In the literature, the photodetection range of Si:Te extends to a wavelength of 5.0 µm at a temperature of 20 K. The simulation shows that carrier diffusion, driven by concentration gradients, is strongly temperature dependent and impacts transient photoconductivity decay curves. The simulation also revealed that, in the hyperdoped regions, the carrier recombination rate remains independent of temperature.
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This content will become publicly available on March 19, 2026
Engineering ultrafast photoconductive response in two-dimensional SnS2 through metal intercalation
SnS2 is a two-dimensional (2D) layered semiconductor with a visible-range bandgap (~2.3eV), high charge carrier mobility, long carrier lifetimes, and good environmental stability. This study explores the impact of zero-valent metal intercalation into the van der Waals gaps of SnS2 on charge carrier dynamics. We demonstrate that metal intercalation enhances optical absorption in the yellow-to-IR range and induces metal-dependent bandgap shifts. Time-resolved THz spectroscopy reveals that different metals uniquely influence photoconductivity dynamics: We find that intercalation with Bi, Ni, and Fe shortens the photoconductivity decay times, whereas Rh intercalation results in a slower decay. These findings highlight the potential of metal intercalation to tailor SnS2 properties for diverse applications, from solar energy conversion to high-speed photodetectors.
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- PAR ID:
- 10620862
- Editor(s):
- Betz, Markus; Elezzabi, Abdulhakem Y
- Publisher / Repository:
- SPIE
- Date Published:
- ISBN:
- 9781510684768
- Page Range / eLocation ID:
- 3
- Format(s):
- Medium: X
- Location:
- San Francisco, United States
- Sponsoring Org:
- National Science Foundation
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