| 1. |
- Argillander, Joakim, et al.
(författare)
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Quantum random number generation based on a perovskite light emitting diode
- 2023
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Ingår i: Communications Physics. - : NATURE PORTFOLIO. - 2399-3650. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- True random number generation is not thought to be possible using a classical approach but by instead exploiting quantum mechanics genuine randomness can be achieved. Here, the authors demonstrate a certified quantum random number generation using a metal-halide perovskite light emitting diode as a source of weak coherent polarisation states randomly producing an output of either 0 or 1. The recent development of perovskite light emitting diodes (PeLEDs) has the potential to revolutionize the fields of optical communication and lighting devices, due to their simplicity of fabrication and outstanding optical properties. Here we demonstrate that PeLEDs can also be used in the field of quantum technologies by implementing a highly-secure quantum random number generator (QRNG). Modern QRNGs that certify their privacy are posed to replace classical random number generators in applications such as encryption and gambling, and therefore need to be cheap, fast and with integration capabilities. Using a compact metal-halide PeLED source, we generate random numbers, which are certified to be secure against an eavesdropper, following the quantum measurement-device-independent scenario. The obtained generation rate of more than 10 Mbit s(-1), which is already comparable to commercial devices, shows that PeLEDs can work as high-quality light sources for quantum information tasks, thus opening up future applications in quantum technologies.
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| 2. |
- Argillander, Joakim, et al.
(författare)
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Secure quantum random number generation with perovskite photonics
- 2024
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Ingår i: QUANTUM COMPUTING, COMMUNICATION, AND SIMULATION IV. - : SPIE-INT SOC OPTICAL ENGINEERING. - 9781510670839 - 9781510670822
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Konferensbidrag (refereegranskat)abstract
- In the field of cryptography, it is crucial that the random numbers used in key generation are not only genuinely random but also private, meaning that no other party than the legitimate user must have information about the numbers generated. Quantum random number generators can offer both properties - fundamentally random output, as well as the ability to implement generators that can certify the amount of private randomness generated, in order to remove some side-channel attacks. In this study we introduce perovskite technology as a resilient platform for photonics, where the resilience is owed to perovskite's ease of manufacturing. This has the potential to mitigate disruptions in the supply chain by enabling local and domestic manufacturing of photonic devices. We demonstrate the feasibility of the platform by implementing a measurement-device independent quantum random number generator based on perovskite LEDs.
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| 3. |
- Bao, Chunxiong, et al.
(författare)
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A multifunctional display based on photo-responsive perovskite light-emitting diodes
- 2024
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Ingår i: NATURE ELECTRONICS. - : NATURE PORTFOLIO. - 2520-1131.
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Tidskriftsartikel (refereegranskat)abstract
- Current display screens are typically only used for information display, but can have a range of different sensors integrated into them for functions such as touch control, ambient light sensing and fingerprint sensing. Photo-responsive light-emitting diodes (LEDs), which can display information and respond to light excitation, could be used to develop future ultra-thin and large screen-to-body ratio screens. However, photo-response is difficult to achieve with conventional display technologies. Here, we report a multifunctional display that uses photo-responsive metal halide perovskite LEDs as pixels. The perovskite LED display can be simultaneously used as a touch screen, ambient light sensor and image sensor (including for fingerprint drawing) without integrating any additional sensors. The light-to-electricity conversion efficiency of the pixels also allow the display to act as a photovoltaic device that can charge the equipment. Photo-responsive metal halide perovskite light-emitting diodes can be used to create a multifunctional display that can function as a touch screen, ambient light sensor and image sensor.
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| 4. |
- Bao, Chunxiong, et al.
(författare)
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Bidirectional optical signal transmission between two identical devices using perovskite diodes
- 2020
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Ingår i: NATURE ELECTRONICS. - : NATURE PUBLISHING GROUP. - 2520-1131. ; 3:3, s. 156-164
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Tidskriftsartikel (refereegranskat)abstract
- A solution-processed perovskite diode that functions as both optical transmitter and receiver can be used to build a monolithic pulse sensor and a bidirectional optical communication system. The integration of optical signal generation and reception into one device-thus allowing a bidirectional optical signal transmission between two identical devices-is of value in the development of miniaturized and integrated optoelectronic devices. However, conventional solution-processable semiconductors have intrinsic material and design limitations that prevent them from being used to create such devices with a high performance. Here we report an efficient solution-processed perovskite diode that is capable of working in both emission and detection modes. The device can be switched between modes by changing the bias direction, and it exhibits light emission with an external quantum efficiency of over 21% and a light detection limit on a subpicowatt scale. The operation speed for both functions can reach tens of megahertz. Benefiting from the small Stokes shift of perovskites, our diodes exhibit a high specific detectivity (more than 2 x 10(12) Jones) at its peak emission (~804 nm), which allows an optical signal exchange between two identical diodes. To illustrate the potential of the dual-functional diode, we show that it can be used to create a monolithic pulse sensor and a bidirectional optical communication system.
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| 5. |
- Bao, Chunxiong, et al.
(författare)
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High Performance and Stable All-Inorganic Metal Halide Perovskite-Based Photodetectors for Optical Communication Applications
- 2018
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Ingår i: Advanced Materials. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095. ; 30:38
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Tidskriftsartikel (refereegranskat)abstract
- Photodetectors are critical parts of an optical communication system for achieving efficient photoelectronic conversion of signals, and the response speed directly determines the bandwidth of the whole system. Metal halide perovskites, an emerging class of low-cost solution-processed semiconductors, exhibiting strong optical absorption, low trap states, and high carrier mobility, are widely investigated in photodetection applications. Herein, through optimizing the device engineering and film quality, high-performance photodetectors based on all-inorganic cesium lead halide perovskite (CsPbIxBr3-x), which simultaneously possess high sensitivity and fast response, are demonstrated. The optimized devices processed from CsPbIBr2 perovskite show a practically measured detectable limit of about 21.5 pW cm(-2) and a fast response time of 20 ns, which are both among the highest reported device performance of perovskite-based photodetectors. Moreover, the photodetectors exhibit outstanding long-term environmental stability, with negligible degradation of the photoresponse property after 2000 h under ambient conditions. In addition, the resulting perovskite photodetector is successfully integrated into an optical communication system and its applications as an optical signal receiver on transmitting text and audio signals is demonstrated. The results suggest that all-inorganic metal halide perovskite-based photodetectors have great application potential for optical communication.
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| 6. |
- Bao, Chunxiong, et al.
(författare)
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Physics of defects in metal halide perovskites
- 2022
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Ingår i: Reports on progress in physics (Print). - : IOP Publishing Ltd. - 0034-4885 .- 1361-6633. ; 85:9
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Forskningsöversikt (refereegranskat)abstract
- Metal halide perovskites are widely used in optoelectronic devices, including solar cells, photodetectors, and light-emitting diodes. Defects in this class of low-temperature solution-processed semiconductors play significant roles in the optoelectronic properties and performance of devices based on these semiconductors. Investigating the defect properties provides not only insight into the origin of the outstanding performance of perovskite optoelectronic devices but also guidance for further improvement of performance. Defects in perovskites have been intensely studied. Here, we review the progress in defect-related physics and techniques for perovskites. We survey the theoretical and computational results of the origin and properties of defects in perovskites. The underlying mechanisms, functions, advantages, and limitations of trap state characterization techniques are discussed. We introduce the effect of defects on the performance of perovskite optoelectronic devices, followed by a discussion of the mechanism of defect treatment. Finally, we summarize and present key challenges and opportunities of defects and their role in the further development of perovskite optoelectronic devices.
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| 7. |
- Chen, Hongting, et al.
(författare)
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High-Efficiency Formamidinium Lead Bromide Perovskite Nanocrystal-Based Light-Emitting Diodes Fabricated via a Surface Defect Self-Passivation Strategy
- 2020
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Ingår i: Advanced Optical Materials. - : WILEY-V C H VERLAG GMBH. - 2162-7568 .- 2195-1071. ; 8:6
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Tidskriftsartikel (refereegranskat)abstract
- Formamidinium lead bromide (FAPbBr(3)) nanocrystals (NCs) demonstrate great potential in light-emitting diode (LED) applications due to their pure green emission and excellent stability. However, the abundant defects at the surface of the NCs act as charge trapping centers and significantly increase the trap-assisted nonradiative recombination channels, hampering the performance improvement of LEDs based on FAPbBr(3) NCs. Herein, a facile self-passivation strategy of the surface defects is developed by introducing excess formamidinium bromide (FABr) during the colloidal synthesis of NCs, leading to much improved photoluminescence quantum yield (PLQY) of the obtained NCs. In addition, enhanced charge transport property is measured in the assembled films owing to the simultaneously declined insulating ligands at the surface of NCs. The molar ratio of FABr and PbBr2 is rationally optimized during the synthesis of NCs and high-efficient green-emissive LEDs are fabricated with a champion current efficiency of 76.8 cd A(-1), corresponding to an external quantum efficiency of 17.1%, which is among the best-performing green LEDs based on perovskite NCs so far.
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| 8. |
- Guo, Ruiqi, et al.
(författare)
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Double Active Layers Constructed with Halide Perovskite and Quantum Dots for Broadband Photodetection
- 2020
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Ingår i: Advanced Optical Materials. - : WILEY-V C H VERLAG GMBH. - 2162-7568 .- 2195-1071. ; 8:17
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Tidskriftsartikel (refereegranskat)abstract
- Herein, solution-processed, high-performance broadband (300-1100 nm) photodetectors based on double active layers incorporating narrow-bandgap CuInSe2 (CISe) quantum dots (QDs) and halide perovskite are devised. The CISe QDs/perovskite film as the photoactive layer boosts the photocurrent and suppresses dark current. Due to the joint light absorption effect of CISe QDs and halide perovskite, the photoelectric conversion capacity is improved. Furthermore, CISe QDs as an electron-blocking layer can effectively block electrons to the hole transport layer and reduce the thermal noise. The optimized photodetector exhibits responsivity over 150 mA W-1 in the visible and more than 20 mA W-1 in the near-infrared (800-1000 nm) ranges, specific detectivity of more than 7.0 x 10(12) Jones in the visible region and 7.7 x 10(11) Jones in the near-infrared region, a transient response time of 277 ns with the active area of 0.013 cm(2), and a linear dynamic range of approximate to 75 dB. Importantly, the CISe QDs layer makes the perovskite denser and more hydrophobic, thus improves the environmental and thermal stability of the detector, even extends the working temperature to exceeding 150 degrees C. The design concept and the considerable performance of this novel device provide a reference value for polychromatic light detection.
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| 9. |
- Jiang, Jizhong, et al.
(författare)
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Synergistic strain engineering of perovskite single crystals for highly stable and sensitive X-ray detectors with low-bias imaging and monitoring
- 2022
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Ingår i: Nature Photonics. - : Nature Portfolio. - 1749-4885 .- 1749-4893. ; 16:8, s. 575-581
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Tidskriftsartikel (refereegranskat)abstract
- X-ray detectors based on dual-site-doped perovskite single crystals exhibit excellent sensitivity of 2.6 x 10(4) mu C Gy(air)(-1) cm(-2) under a low field of 1 V cm(-1). The detectable dose rate is as low as 7.09 nGy(air) s(-1). The operational stability is beyond half a year. Although three-dimensional metal halide perovskite (ABX(3)) single crystals are promising next-generation materials for radiation detection, state-of-the-art perovskite X-ray detectors include methylammonium as A-site cations, limiting the operational stability. Previous efforts to improve the stability using formamidinium-caesium-alloyed A-site cations usually sacrifice the detection performance because of high trap densities. Here we successfully solve this trade-off between stability and detection performance by synergistic composition engineering, where we include A-site alloys to decrease the trap density and B-site dopants to release the microstrain induced by A-site alloying. As such, we develop high-performance perovskite X-ray detectors with excellent stability. Our X-ray detectors exhibit high sensitivity of (2.6 +/- 0.1) x 10(4) mu C Gy(air)(-1) cm(-2) under 1 V cm(-1) and ultralow limit of detection of 7.09 nGy(air) s(-1). In addition, they feature long-term operational stability over half a year and impressive thermal stability up to 125 degrees C. We further demonstrate the promise of our perovskite X-ray detectors for low-bias portable applications with high-quality X-ray imaging and monitoring prototypes.
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| 10. |
- Karlsson, Max, et al.
(författare)
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Mixed halide perovskites for spectrally stable and high-efficiency blue light-emitting diodes
- 2021
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Bright and efficient blue emission is key to further development of metal halide perovskite light-emitting diodes. Although modifying bromide/chloride composition is straightforward to achieve blue emission, practical implementation of this strategy has been challenging due to poor colour stability and severe photoluminescence quenching. Both detrimental effects become increasingly prominent in perovskites with the high chloride content needed to produce blue emission. Here, we solve these critical challenges in mixed halide perovskites and demonstrate spectrally stable blue perovskite light-emitting diodes over a wide range of emission wavelengths from 490 to 451 nanometres. The emission colour is directly tuned by modifying the halide composition. Particularly, our blue and deep-blue light-emitting diodes based on three-dimensional perovskites show high EQE values of 11.0% and 5.5% with emission peaks at 477 and 467 nm, respectively. These achievements are enabled by a vapour-assisted crystallization technique, which largely mitigates local compositional heterogeneity and ion migration.
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