| 1. |
- Li, Guohui, et al.
(författare)
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Room-Temperature Single-Mode Plasmonic Perovskite Nanolasers with Sub-Picosecond Pulses
- 2024
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Ingår i: Advanced Functional Materials. - 1616-301X.
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Tidskriftsartikel (refereegranskat)abstract
- With the explosive growth of communication traffic, increasing the modulation bandwidth of semiconductor lasers has attracted significant attention. However, after rapid progress is achieved, further increasing the modulation bandwidth of semiconductor lasers is hampered by the slow charge-carrier dynamics. Here, a room temperature, single-mode perovskite nanolaser with sub-picosecond pulses, enabled by high Purcell enhancement is reported. This enhancement is achieved via transferring an atomically smooth perovskite nanoplatelet onto the surface of an ultra-smooth SiO2/Ag film. This nanolaser features a low mode volume (V) as low as 0.137 µm3, a high-quality factor (Q) up to 2180, and a low lasing threshold of 36.65 µJ cm−2. The Q value of the laser is one order of magnitude higher than that of state-of-the-art nanolasers. The smoothness of both the nanoplatelet and the SiO2/Ag film in the laser is critical to achieving a high Purcell enhancement. Polarization analysis reveals that the laser emission consists of a transvere-magnetic (TM) polarized surface plasmon mode and a transverse-electric (TE) polarized photonic mode. Furthermore, ultrafast charge-carrier dynamics indicate the surface plasmon decay time can be as short as 0.6 ± 0.4 ps due to the high Purcell enhancement. This work opens up the possibility of developing nanolasers with high bandwidths and ultra-small sizes.
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| 2. |
- Li, Guohui, et al.
(författare)
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Localized Bound Multiexcitons in Engineered Quasi-2D Perovskites Grains at Room Temperature for Efficient Lasers
- 2023
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Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 35:20
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Tidskriftsartikel (refereegranskat)abstract
- Reducing the excitation threshold to minimize the Joule heating is critical for the realization of perovskite laser diodes. Although bound excitons are promising for low threshold laser, how to generate them at room temperature for laser applications is still unclear in quasi-2D perovskite-based devices. In this work, via engineering quasi-2D perovskite PEA2(CH3NH3)n-1PbnBr3n+1 microscopic grains by the anti-solvent method, room-temperature multiexciton radiative recombination is successfully demonstrated at a remarkably low pump density of 0.97 µJ cm−2, which is only one-fourth of that required in 2D CdSe nanosheets. In addition, the well-defined translational momentum in quasi-2D perovskite grains can restrict the Auger recombination which is detrimental to radiative emission. Furthermore, the quasi-2D perovskite grains are favorable for increasing binding energies of excitons and biexcitons and so as the related radiative recombination. Consequently, the prepared phase quasi-2D perovskite film renders a threshold of room-temperature stimulated emission as low as 13.7 µJ cm−2, reduced by 58.6% relative to the amorphous counterpart with larger grains. The findings in this work are expected to facilitate the development of solution-processable perovskite multiexcitonic laser diodes.
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| 3. |
- Zhao, Kefan, et al.
(författare)
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High-Quality Solution-Processed Quasi-2D Perovskite for Low-Threshold Lasers
- 2024
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Ingår i: ACS Applied Materials and Interfaces. - 1944-8244. ; 16:17, s. 22361-22368
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Tidskriftsartikel (refereegranskat)abstract
- Spin-coated quasi-two-dimensional halide perovskite films, which exhibit superior optoelectronic properties and environmental stability, have recently been extensively studied for lasers. Crystallinity is of great importance for the laser performance. Although some parameters related to the spin-coating process have been studied, the in-depth understanding and effective control of the acceleration rate on two-dimensional perovskite crystallization during spin-coating are still unknown. Here we investigate the effect of solvent evaporation on the microstructure of the final perovskite films during the spin-coating process. The crystallization quality of the film can be significantly improved by controlling solvent evaporation. As a result, the prepared quasi-2D perovskite film exhibits a stimulated emission threshold (pump: 343 nm, 6 kHz, 290 fs) of 550 nm as low as 16.2 μJ/cm2. Transient absorption characterization shows that the radiative biexciton recombination time is reduced from 738.5 to 438.3 ps, benefiting from the improved crystallinity. The faster biexciton recombination significantly enhanced the photoluminescence efficiency, which is critical for population inversion. This work could contribute to the development of low-threshold lasers.
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