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- 2019
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Tidskriftsartikel (refereegranskat)
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- Hussain, Laiq, 1979-, et al.
(författare)
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SWIR-LWIR Photoluminescence from Sb-based Epilayers Grown on GaAs Substrates by using MBE
- 2018
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Ingår i: Journal of the Korean Physical Society. - : Korean Physical Society. - 0374-4884 .- 1976-8524. ; 73:11, s. 1604-1611
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Tidskriftsartikel (refereegranskat)abstract
- Utilizing Sb-based bulk epilayers on large-scale low-cost substrates such as GaAs for fabricating infrared (IR) photodetectors is presently attracting significant attention worldwide. For this study, three sample series of GaAsxSb1−x, In1−xGaxSb, and InAsxSb1−x with different compositions were grown on semi-insulating GaAs substrates by using molecular beam epitaxy (MBE) and appropriate InAs quantum dots (QDs) as a defect-reduction buffer layer. Photoluminescence (PL) signals from these samples were observed over a wide IR wavelength range from 2 μm to 12 μm in agreement with the expected bandgap, including bowing effects. In particular, interband PL signals from InAsxSb1−x and In1−xGaxSb samples even at room temperature show promising potential for IR photodetector applications.
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| 3. |
- Wang, Jun, et al.
(författare)
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A New Method to Improve Running Economy and Maximal Aerobic Power in Athletes : Endurance Training With Periodic Carbon Monoxide Inhalation
- 2019
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Ingår i: Frontiers in Physiology. - Lausanne : Frontiers Media S.A.. - 1664-042X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Background: Altitude training stimulates erythropoietin hormone (EPO) release and increases blood hemoglobin (Hb) mass, which may result in improved oxygen (O-2) transport capacity. It was hypothesized in the present study that periodic inhalation of carbon monoxide (CO) might elicit similar physiological adaptations compared to altitude training.Methods: Twelve male college student athletes, who were well-trained soccer players, participated. They performed a 4-week treadmill-training program, five times a week. Participants were randomly assigned into an experimental group with inhaling CO (INCO) (1 mL/kg body weight for 2 min) in O-2 (4 L) before all training sessions and a control group without inhaling CO (NOCO). CO and EPO concentrations in venous blood were first measured acutely at the 1st, 2nd, 4th, 6th, and 8th hour after INCO, and total hemoglobin mass (tHb), running economy and VO(2)max were measured before and after the 4 weeks training intervention.Results: HbCO% increased from 0.7 to 4.4% (P < 0.05) after 1 h of CO inhalation and EPO increased from 1.9 to 2.7 mIU/mL after 4 h post CO inhalation (P < 0.05) acutely before the intervention. After the training, the tHb and VO(2)max in the INCO group increased significantly by 3.7 and 2.7%, respectively, while no significant differences were observed in the NOCO condition. O-2 uptake at given submaximal speeds declined by approximately 4% in the INCO group.Conclusion: Acutely, EPO increased sharply post CO inhalation, peaking at 4 h post inhalation. 4-weeks of training with CO inhalation before exercise sessions improved tHb and VO(2)max as well as running economy, suggesting that moderate CO inhalation could be a new method to improve the endurance performance in athletes. © 2019 Frontiers Media S.A. All Rights Reserved.
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| 4. |
- Wang, Qin, et al.
(författare)
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MWIR interband transitions in type-II (III) In(GaAl)Sb quantum dots
- 2015
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Konferensbidrag (refereegranskat)abstract
- In this work we present an alternative approach for realizing desired IR devices with appropriate operating wavelengths in the MWIR region utilizing In(GaAl)Sb quantum dots embedded in an InAs matrix grown by MBE. The QDs exhibit spatially indirect interband transitions in a type-II broken bandgap alignment, with a transition energy that can be tuned by bandgap and strain engineering utilizing either the quantum dot size or the incorporation of Ga or (GaAl) into the QDs. Furthermore, the growth of such QDs does not require sophisticated epitaxial designs needed for superlattices or quantum cascade structures regarding large numbers of alternating layers and very exact interfaces. The QD structures are expected to exhibit key advantages for IR devices e.g. higher operating temperature, lower power consumption, size, weight, and cost. The structural and composition properties of designed and grown In(GaAl)Sb QDs were characterized using AFM, SEM, TEM, and XRD. The corresponding optical properties, both in terms of absorption and emission, were analyzed and compared for selected QD samples before and after annealing at 650 °C.
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