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Pastor Pastor, David and Dissanayake, Sashini Senali and Ferdous, Naheed and Gandhi, Hemi H. and Tran, Tuan T. and Williams, Jim S. and Aziz, Michael J. and Mazur, Eric and Ertekin, Elif and Sher, Meng-Ju (2021) Carrier Dynamics and Absorption Properties of Gold-Hyperdoped Germanium:Insight Into Tailoring Defect Energetics. Physical review applied, 15 (064058). pp. 1-9. ISSN 2331-7019
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Official URL: https://doi.org/10.1103/PhysRevApplied.15.064058
Abstract
Hyperdoping germanium with gold is a potential method to produce room-temperature shortwavelength-infrared radiation (SWIR; 1.4–3.0 μm) photodetection. We investigate the charge carrier dynamics, light absorption, and structural properties of gold-hyperdoped germanium (Ge:Au) fabricated with varying ion implantation and nanosecond pulsed laser melting conditions. Time-resolved terahertz spectroscopy (TRTS) measurements show that Ge:Au carrier lifetime is significantly higher than that in previously studied hyperdoped silicon systems. Furthermore, we find that lattice composition, sub-bandgap optical absorption, and carrier dynamics depend greatly on hyperdoping conditions. We use density functional theory (DFT) to model dopant distribution, electronic band structure, and optical absorption.
These simulations help explain experimentally observed differences in optical and optoelectronic behavior across different samples. DFT modeling reveals that substitutional dopant incorporation has the lowest formation energy and leads to deep energy levels. In contrast, interstitial or dopant-vacancy complex incorporation yields shallower energy levels that do not contribute to sub-band-gap light absorption and have a small effect on charge carrier lifetimes. These results suggest that it is promising to tailor dopant incorporation sites of Ge:Au for SWIR photodetection applications.
Resumen (otros idiomas)
Hyperdoping germanium with gold is a potential method to produce room-temperature shortwavelength-infrared radiation (SWIR; 1.4–3.0 μm) photodetection. We investigate the charge carrier dynamics, light absorption, and structural properties of gold-hyperdoped germanium (Ge:Au) fabricated with varying ion implantation and nanosecond pulsed laser melting conditions. Time-resolved terahertz spectroscopy (TRTS) measurements show that Ge:Au carrier lifetime is significantly higher than that in previously studied hyperdoped silicon systems. Furthermore, we find that lattice composition, sub-bandgap optical absorption, and carrier dynamics depend greatly on hyperdoping conditions. We use density functional theory (DFT) to model dopant distribution, electronic band structure, and optical absorption. These simulations help explain experimentally observed differences in optical and optoelectronic behavior across different samples. DFT modeling reveals that substitutional dopant incorporation has the lowest formation energy and leads to deep energy levels. In contrast, interstitial or dopant-vacancy complex incorporation yields shallower energy levels that do not contribute to sub-band-gap light absorption and have a small effect on charge carrier lifetimes. These results suggest that it is promising to tailor dopant incorporation sites of Ge:Au for SWIR photodetection applications
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | Implantación iónica; tiempo de vida de las cargas; Germanio hiperdopado; fundido laser de nanosegundos; racocido láser |
| Palabras clave (otros idiomas): | Ion implantation; Carrier lifetime; Hyperdoped Germanium; Pulsed laser melting; laser annealing |
| Subjects: | Sciences > Physics Sciences > Physics > Electronics Sciences > Physics > Materials Sciences > Physics > Solid state physics |
| ID Code: | 70233 |
| Deposited On: | 11 Feb 2022 08:14 |
| Last Modified: | 11 Feb 2022 11:45 |
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