APS March Meeting 2016
Volume 61, Number 2
Monday–Friday, March 14–18, 2016;
Baltimore, Maryland
Session E12: Mechanisms for Long Carrier Lifetimes and High Detectivities from Novel Ga-free Narrow Gap III-V Semiconductor Superlattices
8:00 AM–11:00 AM,
Tuesday, March 15, 2016
Room: 308
Sponsoring
Units:
FIAP DMP
Chair: Michael Flatte, Univ of Iowa
Abstract ID: BAPS.2016.MAR.E12.1
Abstract: E12.00001 : Ga-free InAs/InAsSb type-II superlattice and its applications to IR lasers and photodetectors
8:00 AM–8:36 AM
Preview Abstract
Abstract
Author:
Yong-Hang Zhang
(Arizona State University)
This talk will review the research on Ga-free InAs/InAsSb type-II
superlattices (T2SL), especially their growth, structural and electronic
properties, and applications to IR lasers and photodetectors with the
following highlights: 1) Review of the previous study of InAs/InAsSb T2SL
and its application to IR lasers and photodetectors in the 90's. 2) Long
minority carrier lifetime up to 12.8 $\mu $s in mid-wavelength infrared
(MWIR) InAs/InAsSb T2SL was observed at 15 K, and 412 ns for long-wavelength
infrared (LWIR) InAs/InAsSb T2SL were measured using time-resolved
photoluminescence. The record long carrier lifetime in the MWIR range is due
to carrier localization, which is confirmed by a 3 meV blue shift of the
photoluminescence peak energy with increasing temperature from 15 K to 50 K,
along with a photoluminescence linewidth broadening up to 40 K. In contrast,
no carrier localization is observed in the LWIR T2SL. Modeling results show
that carrier localization is stronger in shorter period (9.9 nm) MWIR T2SL
as compared to longer period (24.2 nm) LWIR T2SL, indicating that the
carrier localization originates mainly from InAs/InAsSb interface disorder.
Although carrier localization enhances carrier lifetimes, it also adversely
affects carrier transport. 3) Pressure-dependent photoluminescence (PL)
experiments under hydrostatic pressures up to 2.16 GPa were conducted on a
MWIR InAs/InAsSb T2SL structure at different pump laser excitation powers
and sample temperatures. The results show a pressure coefficient of the T2SL
transition was found to be 93 \textpm 2 meV\textbullet GPa$^{\mathrm{-1}}$;
a clear change in the dominant photo-generated carrier recombination
mechanism from radiative to defect related, providing evidence for a defect
level situated at 0.18 \textpm 0.01 eV above the conduction band edge of
InAs at ambient pressure. 4) LWIR InAs/InAsSb T2SL nBn photodetectors on
GaSb substrates were demonstrated. The typical device consisted of a 2.2
micron thick absorber layer and has a 50{\%} cutoff wavelength of 13.2 $\mu
$m, a measured dark current density of 5e-4 A/cm$^{\mathrm{2}}$ at 77 K
under a bias of -0.3 V, a peak responsivity of 0.24 A/W at 12 $\mu $m and a
maximum RA product of 300 ohm-cm$^{\mathrm{2}}$ at 77 K. The calculated
generation-recombination noise limited specific detectivity (D*) and
experimentally measured D* at 12 $\mu $m and 77 K are 1e10
(cm-Hz$^{\mathrm{1/2}})$/W and 1e8 (cm-Hz$^{\mathrm{1/2}})$/W, respectively.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2016.MAR.E12.1