| 1. |
- Chen, Q., et al.
(author)
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Highly Tensile-Strained Self-Assembled Ge Quantum Dots on InP Substrates for Integrated Light Sources
- 2021
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In: ACS Applied Nano Materials. - : American Chemical Society (ACS). - 2574-0970. ; 4:1, s. 897-906
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Journal article (peer-reviewed)abstract
- Highly tensile-strained Ge quantum dots (TS-Ge-QDs) emitting structures with different size were successfully grown on InP substrates by molecular beam epitaxy. Dislocation-free TS-Ge-QDs were observed by transmission electron microscopy. Finite element modeling indicates a maximum tensile strain of 4.5% in the Ge QDs, which is much larger than the required strain to achieve direct band gap conversion of Ge based on theoretical prediction. Photoluminescence (PL) from a direct band-gap-like transition of TS-Ge-QDs with a peak energy of 0.796 eV was achieved and confirmed by the etch depth-dependent PL, temperature-dependent PL, and excitation-power-dependent PL. In addition, a strong defect-related peak of 1 eV was observed at room temperature. The band structure of the TS-Ge-QDs emitting structures was calculated to support the experimental results of PL spectra. Achieving PL from direct band-gap-like transitions of TS-Ge-QDs provides encouraging evidence of this promising highly tensile strained semiconductor-nanostructure-based platform for future photonics applications such as integrated light sources.
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| 2. |
- Dou, Cheng, et al.
(author)
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Photoluminescence Evolution with Deposition Thickness of Ge Nanostructures Embedded in GaSb
- 2022
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In: Physica Status Solidi (B): Basic Research. - : Wiley. - 1521-3951 .- 0370-1972. ; 259:4
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Journal article (peer-reviewed)abstract
- Herein, low-temperature and temperature-dependent photoluminescence (PL) measurements are carried out on highly tensile-strained Ge nanostructures embedded in GaSb matrix, and the effects of Ge deposition thickness are clarified. The direct-gap transition-related PL feature is successfully identified in the tensile-strained Ge nanostructures. While typical PL thermal quenching is observed for the tensile-strained Ge- and GaSb-related transitions in the samples with a Ge deposition being thinner than the critical thickness, a negative thermal quenching shows up for the GaSb interband transition in the samples with Ge deposition surpassing the critical thickness at which high-density nanoparticles form to relax the strain. A phenomenological thermal-injection model is established of electrons from the tensile-strained Ge layer to the GaSb matrix, the thermal quenching is accounted for, and a ladder-like function of the strain-relaxed Ge is clarified to favor the electron activation. The understanding of the effects of deposition thickness is helpful for the high-performance Ge-based light source for optoelectronic integration.
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| 3. |
- Leung, Ting Fan, et al.
(author)
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Comparative immunogenicity and safety of human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine and 4vHPV vaccine administered according to two- or three-dose schedules in girls aged 9-14 years : Results to month 36 from a randomized trial
- 2018
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In: Vaccine. - : ELSEVIER SCI LTD. - 0264-410X .- 1873-2518. ; 36:1, s. 98-106
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Journal article (peer-reviewed)abstract
- This observer-blind study (clinicaltrials.gov NCT01462357) compared the immunogenicity and safety of two doses (2D) of the HPV-16/18 AS04-adjuvanted vaccine (2D of AS04-HPV-16/18) vs. two or three doses of the 4vHPV vaccine [2D or 3D of 4vHPV] in 1075 healthy girls aged 9-14 years. Girls were randomized (1:1:1) to receive 2D of AS04-HPV-16/18 at months (M) 0, 6 (N = 359), 2D of 4vHPV at MO, 6 (N = 358) or 3D of 4vHPV at MO, 2, 6 (N = 358). 351, 339 and 346 girls, respectively, returned for the concluding visit at M36. Superiority was demonstrated at M7 and M12; comparison of the immune response to both vaccine antigens was made between 2D of AS04-HPV-16/18 and 2D or 3D of 4vHPV at subsequent time points in the according-to-protocol immunogenicity cohort (ATP-I; N = 958 at M36) and the total vaccinated cohort (TVC: N = 1036 at M36). HPV-16/18-specific T-cell- and B-cell-mediated immune responses and safety were also investigated. At M36, anti-HPV-16/18 ELISA responses in the 2D AS04-HPV-16/18 group remained superior to those of the 2D and 3D 4vHPV groups. In the M36 TVC, geometric mean titers were 2.78-fold (HPV-16) and 6.84-fold (HPV-18) higher for 2D of AS04-HPV-16/18 vs. 2D of 4vHPV and 2.3-fold (HPV-16) and 4.14-fold (HPV-18) higher vs. 3D of 4vHPV. Results were confirmed by vaccine pseudovirion-based neutralisation assay. Numbers of circulating CD4(+) T cells and B cells appeared similar across groups. Safety was in line with the known safety profiles of both vaccines. In conclusion, superior HPV-16/18 antibody responses were elicited by 2D of the AS04-HPV-16/18 compared with 2D or 3D of the 4vHPV vaccine in girls aged 9-14 years.
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| 4. |
- Leung, Ting Fan, et al.
(author)
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Comparative immunogenicity and safety of human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine and HPV-6/11/16/18 vaccine administered according to 2-and 3-dose schedules in girls aged 9-14 years : Results to month 12 from a randomized trial
- 2015
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In: Human Vaccines & Immunotherapeutics. - : Informa UK Limited. - 2164-5515 .- 2164-554X. ; 11:7, s. 1689-1702
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Journal article (peer-reviewed)abstract
- This observer-blind study (clinicaltrials.gov NCT01462357) compared the immunogenicity and safety of 2 doses of the HPV-16/18 AS04-adjuvanted vaccine (HPV-16/18(2D)) vs. 2 or 3 doses of the HPV-6/11/16/18 vaccine (HPV-6/11/16/18(2D) and HPV-6/11/16/18(3D)) in healthy girls aged 9-14 y. Girls were randomized (1:1:1) to receive HPV-16/18(2D) at months (M) 0,6 (N = 359), HPV-6/11/16/18(2D) at M0,6 (N = 358) or HPV-6/11/16/18(3D) at M0,2,6 (N = 358). The primary objective was non-inferiority/superiority of HPV-16/18 antibodies by ELISA for HPV-16/18(2D) vs. HPV-6/11/16/18(2D) at M7 in the according-to-protocol immunogenicity cohort (ATP-I) and total vaccinated cohort, respectively. Secondary objectives included non-inferiority/superiority of HPV-16/18(2D) vs. HPV-6/11/16/18(3D) at M7, non-inferiority/superiority at M12, HPV-16/18 neutralizing antibodies, frequencies of T-cells/B-cells, reactogenicity and safety. Antibody responses at M7 for HPV-16/18(2D) were superior to those for HPV-6/11/16/18(2D) and HPV-6/11/16/18(3D) (lower limit of 95% confidence interval for geometric mean titer ratio (GMR) was >1): HPV-16/18(2D)/HPV-6/11/16/18(2D) GMRs were 1.69 [1.49-1.91] for anti-HPV-16 and 4.52 [3.97-5.13] for anti-HPV-18; HPV-16/18(2D)/HPV-6/11/16/18(3D) GMRs were 1.72 [1.54-1.93] for anti-HPV-16 and 3.22 [2.82-3.68] for anti-HPV-18; p = 0.0001 for all comparisons. Non-inferiority/superiority was also demonstrated at M12. Among initially seronegative girls in the ATP-I, neutralizing antibody titers were at least 1.8-fold higher for HPV-16/18(2D) vs. HPV-6/11/16/18(2D) and HPV-6/11/16/18(3D) at M7 and M12. Frequencies of HPV-16/18-specific T-cells and B-cells were in similar ranges between groups. Reactogenicity and safety were in line with the known profile of each vaccine. In conclusion, superior HPV-16/18 antibody responses were elicited by 2 doses of the HPV-16/18 AS04-adjuvanted vaccine compared with 2 or 3 doses of the HPV-6/11/16/18 vaccine in girls (9-14years).
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