| 1. |
- Wang, Heyong, et al.
(författare)
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Tin-Halide Perovskites for Near-Infrared Light-Emitting Diodes
- 2024
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Ingår i: ACS Energy Letters. - : AMER CHEMICAL SOC. - 2380-8195.
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Forskningsöversikt (refereegranskat)abstract
- Light-emitting diodes (LEDs) with different emission spectra are widely used in daily life for a variety of applications. However, due to fundamental restrictions of light-emitting materials, the development of near-infrared LEDs (NIR-LEDs) is still modest. Recently, solution-processed tin-halide perovskites (THPs) have emerged as one of the most promising light-emitting materials for NIR-LED applications. In this Perspective, we start with discussing the peculiarities of THP semiconductors and how their electronic properties affect the light emission efficiency. We then summarize the current efforts in material engineering to design and master the electronic properties of THP films. Finally we give an outlook on the future challenges and technical roadmap for tin-based perovskite LEDs.
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| 2. |
- Yuan, Fanglong, et al.
(författare)
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Bright and stable near-infrared lead-free perovskite light-emitting diodes
- 2024
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Ingår i: Nature Photonics. - : NATURE PORTFOLIO. - 1749-4885 .- 1749-4893.
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Tidskriftsartikel (refereegranskat)abstract
- Long-wavelength near-infrared light-emitting diodes (NIR LEDs) with peak emission wavelengths beyond 900 nm are of critical importance for various applications including night vision, biomedical imaging, sensing and optical communications. However, the low radiance and poor operational stability of state-of-the-art long-wavelength NIR LEDs based on soft materials remain the most critical factors limiting their practical applications. Here we develop NIR LEDs emitting beyond 900 nm with improved performance through the rational manipulation of p doping in all-inorganic tin perovskites (CsSnI3) by retarding and controlling the crystallization process of perovskite precursors in tin-rich conditions. The resulting NIR LEDs exhibit a peak emission wavelength at 948 nm, high radiance of 226 W sr-1 m-2 and long operational half-lifetime of 39.5 h at a high constant current density of 100 mA cm-2. Our demonstration of efficient and stable NIR LEDs operating at high current densities may also open up new opportunities towards electrically pumped lasers. Controlling the intrinsic doping of lead-free perovskites enables near-infrared LEDs emitting at 948 nm with a peak radiance of 226 W sr-1 m-2 and a half-lifetime of 39.5 h.
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| 3. |
- Zhou, Yang, et al.
(författare)
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How Photogenerated I2 Induces I-Rich Phase Formation in Lead Mixed Halide Perovskites
- 2023
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Ingår i: Advanced Materials. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095.
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Tidskriftsartikel (refereegranskat)abstract
- Bandgap tunability of lead mixed halide perovskites (LMHPs) is a crucial characteristic for versatile optoelectronic applications. Nevertheless, LMHPs show the formation of iodide-rich (I-rich) phase under illumination, which destabilizes the semiconductor bandgap and impedes their exploitation. Here, it is shown that how I-2, photogenerated upon charge carrier trapping at iodine interstitials in LMHPs, can promote the formation of I-rich phase. I-2 can react with bromide (Br-) in the perovskite to form a trihalide ion I2Br- (I delta--I delta+-Br delta-), whose negatively charged iodide (I delta-) can further exchange with another lattice Br- to form the I-rich phase. Importantly, it is observed that the effectiveness of the process is dependent on the overall stability of the crystalline perovskite structure. Therefore, the bandgap instability in LMHPs is governed by two factors, i.e., the density of native defects leading to I-2 production and the Br- binding strength within the crystalline unit. Eventually, this study provides rules for the design of chemical composition in LMHPs to reach their full potential for optoelectronic devices.
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