Electrical properties of short period InAs/GaSb superlattice (original) (raw)
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Temperature dependence performances of InAs/GaSb superlattice photodiode
Infrared Physics & Technology, 2011
In this communication we report on temperature dependence performances of short period InAs/GaSb pin superlattice (SL) photodiode grown by Molecular Beam Epitaxy on p-type GaSb substrate. SL symmetrical structure with 3 lm thick active region, adapted for detection in the MWIR domain with cutoff wavelength varying from 4.6 lm to 5.5 lm in the temperature range 80-300 K, was processed in mesa photodiode in order to perform dark current measurements as a function of temperature. Extracted from current-voltage characteristics, R 0 A products above 1 Â 10 6 X cm 2 at 80 K and around 0.15 X cm 2 at 200 K were measured, and the quantitative analysis of the J-V curves allowed us to identify the dominant dark current mechanism in each operating temperature range. As a result, SL photodiode is dominated by generation-recombination (GR) processes at low temperature and becomes diffusion limited above 140 K. Such results are discussed and minority carrier lifetimes were extracted from J-V curve fitting.
Transport measurements on InAs/GaSb superlattice structures for mid-infrared photodiode
Journal of Physics: Conference Series, 2009
In this communication, we report on electrical transport measurements of nonintentionally doped InAs/GaSb Superlattice structures grown by Molecular Beam Epitaxy. Resistivity and Hall Effect measurements were performed on two samples, corresponding to the same SL structure that has been grown on two different substrates: one on semi-insulating GaAs substrate, another on n-type GaSb substrate. To carry out the electrical measurements, the conducting GaSb substrate of the second sample has been removed. The study were performed in the temperature range 77-300K, for magnetic fields of 0.38 T.. The both samples exhibited a change in type of conductivity from p-type at low temperature to n-type near room temperature.
Investigation of impurities in type-II InAs/GaSb superlattices via capacitance-voltage measurement
Capacitance-voltage measurement was utilized to characterize impurities in the non-intentionally doped region of Type-II InAs/GaSb superlattice p-i-n photodiodes. Ionized carrier concentration versus temperature dependence revealed the presence of a kind of defects with activation energy below 6 meV and a total concentration of low 10 15 cm À3 . Correlation between defect characteristics and superlattice designs was studied. The defects exhibited a p-type behavior with decreasing activation energy as the InAs thickness increased from 7 to 11 monolayers, while maintaining the GaSb thickness of 7 monolayers. With 13 monolayers of InAs, the superlattice became n-type and the activation energy deviated from the p-type trend. V C 2013 AIP Publishing LLC.
Characterization of midwave infrared InAs/GaSb superlattice photodiode
Journal of Applied Physics, 2009
We report on structural, electrical, and optical characterizations of midwave infrared InAs/GaSb superlattice ͑SL͒ p-i-n photodiodes. High-quality SL samples, with 1 m thick active region ͑220 SL periods͒, exhibited a cut-off wavelength of 4.9 m at 80 K. Using a capacitance-voltage measurement technique performed on mesa diode, the residual background concentration in the nonintentionally doped region was determined to be 3 ϫ 10 15 cm −3 at 80 K. Extracted from current-voltage characteristics, R 0 A products above 4 ϫ 10 5 ⍀ cm 2 at 80 K were measured, and the quantitative analysis of the J-V curves showed that the dark current density of SL photodiode is dominated by generation-recombination processes. Front-side illuminated photodiodes produced responsivity at 80 K equal to 360 mA/W at 4.5 m.
In this paper, quantum efficiency (QE) measurements performed on type-II InAs/GaSb superlattice (T2SL) photodiodes operating in the mid-wavelength infrared domain, are reported. Several comparisons were made in order to determine the SL structure showing optimum radiometric performances : same InAs-rich SL structure with different active zone thicknesses (from 0.5µm to 4µm) and different active zone doping (n-type versus p-type), same 1µm thick p-type active zone doping with different SL designs (InAs-rich versus GaSbrich and symmetric SL structures). Best result was obtained for the p-type doped InAs-rich SL photodiode, with a 4µm active zone thickness, showing a QE that reaches 61% at λ = 2µm and 0V bias voltage.
Electrical characterizations of asymmetric InAs/GaSb superlattice MWIR photodiodes
Infrared Physics & Technology, 2013
InAs/GaSb superlattice pin photodiodes, having an asymmetric period design, exhibited cut-off wavelength in the midwave infrared domain (MWIR) at 5 lm at 77 K. Electrical characterizations including dark-current and capacitance-voltage measurements were performed on single detectors in the temperature range (77-300 K). The SL photodiode measurements revealed carrier concentrations of about 6 Â 10 14 cm À3 at 77 K, dark-current densities J = 4 Â 10 À8 A/cm 2 at 77 K for V bias = À50 mV and the measured R 0 A product is higher than 1.5 Â 10 6 X cm 2 at 77 K. Comparison to classical pin diodes with symmetric period design show that the differential resistance area product is improved by more than one order of magnitude. This result obtained demonstrates the strong influence of the period on the electrical properties of SL MWIR photodiodes.
Journal of Electronic Materials, 2012
A midwave infrared pin photodiode based on a type II InAs/GaSb superlattice (SL) was fabricated, and electrical measurements under dark conditions were performed as a function of temperature. The SL structure exhibits photoluminescence emission at 4.55 lm at 77 K. Deduced from current densityvoltage (J-V) measurements, a zero-bias resistance-area product R 0 A greater than 1 9 10 6 X cm 2 at 77 K was measured. Additional noise measurements show no presence of intrinsic 1/f noise above 20 Hz, and the photodiode presents Schottky-limited behavior below À600 mV. All these results confirm the potential for such SL InAs/GaSb superlattice pin photodiodes operating in the midwave infrared domain.
Growth and characterization of InAs/GaSb photoconductors for long wavelength infrared range
Applied Physics Letters, 1997
In this letter we report the molecular beam epitaxial growth and characterization of InAs/GaSb superlattices grown on semi-insulating GaAs substrates for long wavelength infrared detectors. Photoconductive detectors fabricated from the superlattices showed photoresponse up to 12 m and peak responsivity of 5.5 V/W with Johnson noise limited detectivity of 1.33ϫ10 9 cm Hz 1/2 /W at 10.3 m at 78 K. © 1997 American Institute of Physics. ͓S0003-6951͑97͒03236-1͔
Electrical performance of InAs/AlSb/GaSb superlattice photodetectors
Superlattices and Microstructures, 2016
Temperature dependence of dark current measurements is an efficient way to verify the quality of an infrared detector. Low dark current density values are needed for high performance detector applications. Identification of dominant current mechanisms in each operating temperature can be used to extract minority carrier lifetimes which are highly important for understanding carrier transport and improving the detector performance. InAs/AlSb/GaSb based T2SL N-structures with AlSb unipolar barriers are designed for low dark current with high resistance and detectivity. Here we present electrical and optical performance of such N-structure photodetectors.