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Light or Heat: What Is Killing Lead Halide Perovskites Under Solar Cell Operation Conditions?
摘要： We report the first systematic assessment of intrinsic photothermal stability of a large panel of complex lead halides APbX3 incorporating different univalent cations (A=CH3NH3+, [NH2CHNH2]+, Cs+) and halogen anions (X=Br, I) using a series of analytical techniques such as UV-vis and x-ray photoelectron spectroscopy, x-ray diffraction, EDX analysis, atomic force and scanning electron microscopy, ESR spectroscopy and mass spectrometry. We show that heat stress and light soaking induce a severe degradation of perovskite films even in the absence of oxygen and moisture. The stability of complex lead halides increases in the order MAPbBr3<MAPbI3<FAPbI3<FAPbBr3<CsPbI3<CsPbBr3, thus featuring all-inorganic perovskites as the most promising absorbers for stable perovskite solar cells. An important correlation was found between the stability of the complex lead halides and the volatility of univalent cation halides incorporated in their structure. The established relationship provides useful guidelines for designing new complex metal halides with immensely improved stability.
关键词： Plasmonics and Optoelectronics,Photothermal Stability,Solar Cell Operation Conditions,Energy Conversion and Storage,Lead Halide Perovskites
更新于2025-09-12 10:27:22
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Dark sub-gap states in metal-halide perovskites revealed by coherent multidimensional spectroscopy
摘要： Metal-halide perovskites show excellent properties for photovoltaic and optoelectronic applications, with power conversion efficiencies of solar cell and LEDs exceeding 20%. Being solution processed, these polycrystalline materials likely contain a large density of defects compared to melt-grown semiconductors. Surprisingly, typical effects from defects (absorption below the bandgap, low fill factor and open circuit voltage in devices, strong non-radiative recombination) are not observed. In this work, we study thin films of metal-halide perovskites CH3NH3PbX3 (X = Br,I) with ultrafast multidimensional optical spectroscopy to resolve the dynamics of band and defect states. We observe a shared ground state between the band-edge transitions and a continuum of sub-bandgap states, which extends at least 350 meV below the band edge). We explain the comparatively large bleaching of the dark sub-bandgap states with oscillator strength borrowing from the band-edge transition. Our results show that upon valence to conduction band excitation such sub-gap states are instantaneously bleached for large parts of the carrier lifetime and conversely, that almost dark sub-bandgap states can be populated by light excitation. This observation helps unraveling the photophysical origin of the unexpected optoelectronic properties of these materials.
关键词： photovoltaic,defect states,metal-halide perovskites,optoelectronic,ultrafast multidimensional optical spectroscopy
更新于2025-09-12 10:27:22
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UV Resin Enhanced Stability of Metal Halide Perovskite Nanocrystals for White Light-Emitting Diodes
摘要： The long-term stability issue of metal halide perovskite nanocrystals (NCs) is one of the challenges for the applications in optoelectronic devices. Herein, we demonstrate the enhanced air, moisture, and light stability of these NCs by encapsulation into UV Resin (UVR). As prepared perovskite NCs-UVR composites exhibit well maintained optical properties. In addition, the composites show excellent stability with almost identical luminescent behavior for more than 60 days upon continuous exposure in air, moisture, light irradiation, which is superior to the other previous reports. Moreover, we have used these green- and red-emitting composite sheets to fabricate white light-emitting diodes (LEDs) by stacking them on top of the blue LED. We observed a bright neutral white light with a correlated color temperature of 5623 K, a color-rendering index of 85, and a high luminous efficacy of radiation (~349 lm/W). Our findings show the great potential of employing this technique for diverse photonic applications.
关键词： halide perovskites,UV resin,air and moisture stability,white light-emitting diodes,polymerization
更新于2025-09-12 10:27:22
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High perovskite-to-manganese energy transfer efficiency in single-component white-emitting Mn-doped halide perovskite quantum dots
摘要： Taking advantages of negligible reabsorption and no phase separation, single-component white-emitting phosphors are believed as new promising color conversion materials for white light-emitting diodes. As a potential candidate, Mn-doped lead halide perovskites are studied intensively, but rare works can realize pure white emission with a single component due to the challenge for realizing sufficient energy transfer efficiency from perovskite to Mn at the desirable emission wavelengths. In this work, we reported the synthesis of single-component white light halide perovskite quantum dots (QDs) by doping Mn into the host of CsPb(Cl/Br)3@CsPb(Cl/Br)x core–amorphous shell (CAS). The small size of zero-dimensional core in CAS structure has a strong quantum confinement effect, which can enhance the energy transfer efficiency from halide perovskite to Mn impurity dramatically. Our result shows 19.3 times higher energy transfer efficiency for Mn-doped CAS than that of ordinary Mn-doped CsPb(Cl/Br)3 nanocubes. As a result, as-prepared Mn-doped CAS QDs give rise to a white light emission with Commission Internationale de l’Eclairage (CIE) color coordinates of (0.37, 0.33). After blending with polystyrene (PS), Mn-doped CAS QDs can be used as a single-component color conversion material for assembling white light LEDs.
关键词： energy transfer efficiency,white-emitting phosphors,white light LEDs,Mn-doped lead halide perovskites,quantum dots
更新于2025-09-12 10:27:22
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2D Nanoplates and Scaled-up Bulk Polycrystals of Ruddlesden-Popper, Cs2PbI2Cl2 for Optoelectronic Applications
摘要： Two-dimensional (2D) layered Ruddlesden-Popper (RP) phases of halide perovskite offer exotic properties and interesting structure, which make them suitable candidate for solar photovoltaics, light emitting diode (LED) and photodetector applications. Simple and scaled-up synthesis, chemical transformations, doping and stability are the important steps towards the applications. Herein, all-inorganic RP phase of Cs2PbI2Cl2 was synthesized via a facile hot-injection method using benzoyl halides as halide sources. Different morphologies in the form of 2D nanoplates (NPLs) and small nanocrystals (NCs) were obtained by changing the concentration of capping agents (i.e., oleic acid and oleylamine) in solution. The excitonic absorption peak was appeared for NPLs and NCs, which is the characteristic feature of 2D halide perovskites. Further, the scalable quantity (~1 gm) of bulk powder and micron-sized particles of Cs2PbI2Cl2 were synthesized via liquid assisted mechanochemical grinding and anti-solvent method, respectively. We have performed post-synthetic chemical transformation to synthesize three-dimensional (3D) CsPbBr3 disk-shaped particles and zero-dimensional (0D) Cs4PbCl6 NCs from the pre-synthesized RP Cs2PbI2Cl2 NCs in solution and studied their optical properties. Finally, doping of Mn2+ was carried out in Cs2PbI2Cl2 NCs, which demonstrated typical feature of Mn2+ dopant emission along with host emission properties. Low-temperature (77 K) photoluminescence (PL) spectra reveal red-shifted and line-width broadening emission along with longer PL lifetime for both undoped and Mn-doped NCs compared to room temperature PL. Further, the temperature-dependent PL spectra and thermogravimetric analysis (TGA) revealed excellent thermal stability of Cs2PbI2Cl2. This work offers an insight for exploration of synthesis process, post-synthetic chemical transformation and dopant insertion in all-inorganic 2D RP perovskites, which is important step forward for application. Demonstrations of various simple synthesis of both the nano and bulk phases, structural transformation and detailed optical properties of doped and undoped RP perovskite halide nanostructures unfold innovative opportunities for applicability in optoelectronics such as in solar cell and photodetectors.
关键词： Synthesis,2D Halide Perovskites,Post-synthetic Transformation,Optical Properties,Mn-doping,Thermal Stability,Ruddlesden-Popper Phase
更新于2025-09-12 10:27:22
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Welcoming the First Decade of Perovskite Solar Cells
摘要： The swift emergence of perovskite solar cells (PSCs) is a “miracle” development in the history of photovoltaics. Since Miyasaka and co-workers (Toin University of Yokohama, Japan) reported the ?rst use of halide perovskites (HPs) in solar cells in 2009, the past ten years have witnessed a skyrocketing increase in power conversion ef?ciency (PCE) to 24.2% for single-junction PSCs and 28.0% for Si-perovskite tandem solar cells. Meanwhile, the PSC stability, the Achilles heel of this technology, has been enhanced substantially. While the early versions of PSCs were stable just for a few days, the state-of-the-art PSCs have now demonstrated more than 10,000 hours of operational stability and a few thousand hours of outdoor stability, advancing the practical deployment of PSCs signi?cantly. Such impressive progress in the PCE and stability of PSCs has been not only attributed to the creative technological innovation in device structures, perovskite processing, charge-transport-layer engineering, interface modi?cation, etc., but also related to the fascinating understanding of fundamental sciences in HP materials that include crystal structure, defect chemistry, crystallization, photophysics, and light-matter interaction.
关键词： halide perovskites,perovskite solar cells,photovoltaics,stability,power conversion efficiency
更新于2025-09-11 14:15:04
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Lateral cavity enabled Fabry-Perot microlasers from all-inorganic perovskites
摘要： Microlasers play an important role in the development of photonics and optoelectronics. As the rising star in the semiconductor family, all-inorganic lead halide perovskites (ILHPs) have been recognized as promising optical gain and lasing media. However, until now, achieving duplicable and single-mode microlasers remains a taunting challenge. Herein, we fabricated rectangular-shaped ILHP microsheets by the chemical vapor deposition method. The single-crystalline nature and the atomically smooth surfaces of the sample enable the achievement of lateral-cavity Fabry–P(cid:2)erot (F-P) microlasers. Speci?cally, the lasing characteristics including the wavelength, mode spacing, and Q-factors can be well-reproduced along the axial direction of the individual microsheet. By regulating the width of the ILHP microsheet, the desirable single-longitudinal mode F-P microlaser was eventually achieved. Our results provide an enabling coherent light source for optics-related applications.
关键词： microlasers,all-inorganic lead halide perovskites,Fabry–P(cid:2)erot,single-mode lasing,chemical vapor deposition
更新于2025-09-11 14:15:04
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Monocrystalline Perovskite Wafer/Thin Film for Photovoltaic and Transistors Applications
摘要： High-purity monocrystalline silicon has a long history in development of photovoltaics and so far has dominated the modern computers with its profound implementations in transistors and chips. The success of silicon has shown that monocrystalline wafers/thin films of semiconducting materials which have superior electronic properties are good platform for these optoelectronic and electronic applications. Recently, the newly emerging semiconducting materials of halide perovskites (HPs) have attracted much attention owing to their continuing success in high-efficiency solar cells. Demonstrated optoelectronic properties of HPs indicate that it could be a promising alternative to the silicon-based semiconducting industry. While the prerequisite of high-efficiency device is the material accessibility of monocrystalline HPs (mono-HP), as can be learned from the lessons of monocrystalline silicon. Current HPs based technologies, in terms of research areas like solar cells, photodetectors, light-emitting diodes (LEDs), lasers and transistors, are bottlenecked in manufacturing the mono-HP wafer/thin film materials, hence lacking exciting results of mono-HP devices. The state-of-the-art optoelectronic HP based devices are exclusively built using polycrystalline thin films, which are limited in their performance due to issues such as grain boundary defects, large trap-density and inhomogeneous charge transport. However, these issues can be resolved by utilizing mono-HPs. In this review, we will manifest in-depth analyses and discussions on the potential of mono-HPs in photovoltaics and transistor applications, and present the remaining challenges as well as promising research strategies to provide direction for future programs.
关键词： thin film,monocrystalline perovskite wafer,halide perovskites,transistors,photovoltaics
更新于2025-09-11 14:15:04
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Recent developments in flexible photodetectors based on metal halide perovskite
摘要： Flexible photodetectors (FPDs) have been receiving increasing attention in recent years because of their potential applications in electronic eyes, bioinspired sensing, smart textiles, and wearable devices. Moreover, metal halide perovskites (MHPs) with outstanding optical and electrical properties, good mechanical flexibility, low-cost and low-temperature solution-processed fabrication have become promising candidates as light harvesting materials in FPDs. Herein, we comprehensively review the developments of FPDs based on MHPs reported recently. This review firstly provides an introduction with respect to the performance parameters and device configurations of perovskite photodetectors, followed by the specific requirements of FPDs including substrate and electrode materials. Next, chemical compositions, structures and preparation methods of MHPs are presented. Then, the FPDs on the basis of single-component perovskite and hybrid structure perovskite are discussed, subsequently, self-powered flexible perovskite photodetectors were presented. In the end, conclusions and challenges are put forward in the field of FPDs based on perovskites.
关键词： metal halide perovskites,flexible photodetectors,self-powered
更新于2025-09-11 14:15:04
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Hot-substrate deposition of all-inorganic perovskite films for low-temperature processed high-efficiency solar cells
摘要： All-inorganic cesium lead halide perovskites (CsPbX3) have emerged as one of the most promising photovoltaic materials due to their superior thermal stability. However, the high phase transition temperatures (typically over 250 ?C) of CsPbX3 perovskites are incompatible with flexible substrates. Herein, we employed a simple hot-casting method to fabricate low-temperature processed CsPbI2Br films. By casting the perovskite precursor solution onto a hot substrate (maintained at 55 ?C), compact, large-grain and pinhole-free CsPbI2Br films can be prepared at a low post-annealing temperature, which outperform the conventional room temperature (RT)-casting and high-temperature (post-annealing at 340 ?C) processed CsPbI2Br films containing some voids. As a result, the hot-casting and low-temperature (post-annealing at 120 ?C) processed CsPbI2Br perovskite solar cells (PSCs) exhibited an outstanding power conversion efficiency (PCE) of 12.5%, which is much higher than that (2.91%) of the RT-casting processed CsPbI2Br devices. Further optimization of the post-annealing temperature (optimized value: 180 ?C) yielded the best performance of 13.8% for hot-casting processed CsPbI2Br devices. This study gives an effective and facile strategy toward low-temperature processed all-inorganic perovskite films and high-performance PSCs.
关键词： hot-casting method,All-inorganic cesium lead halide perovskites,perovskite solar cells,low-temperature processed,CsPbI2Br
更新于2025-09-11 14:15:04