RT Journal Article
T1 Carrier Dynamics and Absorption Properties of Gold-Hyperdoped Germanium:Insight Into Tailoring Defect Energetics
T2 Carrier Dynamics and Absorption Properties of Gold-Hyperdoped Germanium:Insight Into Tailoring Defect Energetics
A1 Pastor Pastor, David
A1 Dissanayake, Sashini Senali
A1 Ferdous, Naheed
A1 Gandhi, Hemi H.
A1 Tran, Tuan T.
A1 Williams, Jim S.
A1 Aziz, Michael J.
A1 Mazur, Eric
A1 Ertekin, Elif
A1 Sher, Meng-Ju
AB 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.
AB 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 carrierdynamics, light absorption, and structural properties of gold-hyperdoped germanium (Ge:Au) fabricatedwith varying ion implantation and nanosecond pulsed laser melting conditions. Time-resolved terahertzspectroscopy (TRTS) measurements show that Ge:Au carrier lifetime is significantly higher than that inpreviously studied hyperdoped silicon systems. Furthermore, we find that lattice composition, sub-bandgap optical absorption, and carrier dynamics depend greatly on hyperdoping conditions. We use densityfunctional 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 lowestformation energy and leads to deep energy levels. In contrast, interstitial or dopant-vacancy complexincorporation yields shallower energy levels that do not contribute to sub-band-gap light absorption andhave a small effect on charge carrier lifetimes. These results suggest that it is promising to tailor dopantincorporation sites of Ge:Au for SWIR photodetection applications
PB Amer Physical Soc
SN 2331-7019
YR 2021
FD 2021-06-23
LK https://hdl.handle.net/20.500.14352/6769
UL https://hdl.handle.net/20.500.14352/6769
LA spa
NO Ministerio de Ciencia e Innovación (MICINN)
NO Comunidad de Madrid/FEDER
NO Department of Defense (DoD)
NO National Defense Science and Engineering Graduate Fellowship (NDSEG) Program
NO Directed Energy Processing Society Graduate Fellowship
DS Docta Complutense
RD 14 may 2025