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- 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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| 2. |
- Wang, Zhongqiang, et al.
(författare)
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Realizing 18.03% efficiency and good junction characteristics in organic solar cells via hydrogen-bonding interaction between glucose and ZnO electron transport layers
- 2022
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 11:4, s. 1810-1816
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Tidskriftsartikel (refereegranskat)abstract
- Electron transport layers (ETLs) with excellent electron extraction capability are essential for realizing high efficiency in organic solar cells (OSCs). A sol-gel-processed ZnO ETL is widely used in OSCs due to its high mobility and suitable work function. However, the existence of defects usually results in low photovoltaic performance during the operation of OSCs. In this work, glucose (Gl) was used to passivate free OH traps via hydrogen-bonding interaction and formed ZnO/Gl ETLs with ZnO, which exhibited improved electron extraction capability and reduced trap defect density. Thus, a champion efficiency of 18.03% was obtained in a PM6:Y6 light absorber-based cell, which is >11% higher than that of the reference cell (16.15%) with a pristine ZnO ETL. Impressive enhancements by >11% were also observed in different fullerene and non-fullerene light absorber-based cells relative to that of the reference cell. This study demonstrates a new strategy to design ETLs for realizing high efficiency in OSCs.
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