Chalcogen-hyperdoped germanium for short-wavelength infrared photodetection
Hemi H. Gandhi,
David Pastor,
Tuan T. Tran,
Stefan Kalchmair,
Lachlan A. Smillie,
Jonathan P. Mailoa,
Ruggero Milazzo,
Enrico Napolitani,
Marko Loncar,
James S. Williams,
Michael J. Aziz,
Eric Mazur
Affiliations
Hemi H. Gandhi
Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, Massachusetts 02138, USA
David Pastor
Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, Massachusetts 02138, USA
Tuan T. Tran
Department of Electronic Materials Engineering, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200, Australia
Stefan Kalchmair
Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, Massachusetts 02138, USA
Lachlan A. Smillie
Department of Electronic Materials Engineering, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200, Australia
Jonathan P. Mailoa
Department of Physics and Astronomy, Ångström Laboratory, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
Ruggero Milazzo
Dipartimento di Fisica e Astronomia, Università di Padova and CNR-IMM, Via Marzolo 8, I-35131 Padova, Italy
Enrico Napolitani
Dipartimento di Fisica e Astronomia, Università di Padova and CNR-IMM, Via Marzolo 8, I-35131 Padova, Italy
Marko Loncar
Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, Massachusetts 02138, USA
James S. Williams
Department of Electronic Materials Engineering, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200, Australia
Michael J. Aziz
Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, Massachusetts 02138, USA
Eric Mazur
Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, Massachusetts 02138, USA
Obtaining short-wavelength-infrared (SWIR; 1.4 μm–3.0 μm) room-temperature photodetection in a low-cost, group IV semiconductor is desirable for numerous applications. We demonstrate a non-equilibrium method for hyperdoping germanium with selenium or tellurium for dopant-mediated SWIR photodetection. By ion-implanting Se or Te into Ge wafers and restoring crystallinity with pulsed laser melting induced rapid solidification, we obtain single crystalline materials with peak Se and Te concentrations of 1020 cm−3 (104 times the solubility limits). These hyperdoped materials exhibit sub-bandgap absorption of light up to wavelengths of at least 3.0 μm, with their sub-bandgap optical absorption coefficients comparable to those of commercial SWIR photodetection materials. Although previous studies of Ge-based photodetectors have reported a sub-bandgap optoelectronic response only at low temperature, we report room-temperature sub-bandgap SWIR photodetection at wavelengths as long as 3.0 μm from rudimentary hyperdoped Ge:Se and Ge:Te photodetectors.
