- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Computational high throughput screening of inorganic cation based halide perovskites for perovskite only tandem solar cells
摘要： We search for homovalent alternatives for A, B, and X-ions in ABX3 type inorganic halide perovskites suitable for tandem solar cell applications. We replace the conventional A-site organic cation CH3NH3, by 3 inorganic cations, Cs, K, and Rb, and the B site consists of metals; Cd, Hg, Ge, Pb, and Sn This work is built on our previous high throughput screening of hybrid perovskite materials (Kar et al 2018 J. Chem. Phys. 149, 214701). By performing a systematic screening study using Density Functional Theory (DFT) methods, we found 11 suitable candidates; 2 Cs-based, 3 K-based and 6 Rb-based that are suitable for tandem solar cell applications.
关键词： tandem solar cells,inorganic perovskites,density functional theory
更新于2025-09-23 15:21:01
-
Robust Wavelength-Converting and Lasing Media from Wafer-Scale Inorganic Perovskites Enabled by a Protective Surface Layer
摘要： Despite that the inorganic halide perovskites show great promise in wavelength-conversion and lasing applications, the stability and scalability remain as the obstruction toward practical applications. Herein, we, for the first time, employ the wafer-scale inorganic perovskite single crystals to address the above issue. Our spectroscopic analysis reveals that the carrier trapping on the crystal surface is the most probable culprit to hinder the optical amplification for the weak-penetrating one-photon pumping, whilst, the interior of the crystal preserves intact and show low-threshold stimulated emission by two-photon absorption in the near infrared regime. Thanks to the effective protection from the surface layer, the stimulated emission maintains 90% of the initial intensity upon uninterrupted pumping of 4 hours and shows nearly constant threshold upon long-term storage without any encapsulation (> one year). By exploiting a parallel-mirror cavity, an optically pumped wavelength-converting and laser device featuring a spatially coherent output beam is constructed. Our finding greatly advances the development of practical coherent light sources based on halide perovskites.
关键词： wavelength-conversion,lasing,scalability,two-photon absorption,inorganic halide perovskites,stability,coherent light sources,stimulated emission
更新于2025-09-23 15:21:01
-
Tin halide perovskite films made of highly oriented 2D crystals enable more efficient and stable lead-free perovskite solar cells
摘要： Low toxicity and an ideal energy bandgap make 2D Ruddlesden-Popper tin-based halide perovskites a promising photovoltaic material. However, the disordered crystal orientation and the oxidation of Sn2+ to Sn4+ still need to be addressed. Here, we demonstrate that the annealing of FASnI3 assisted by phenyl ethyl ammonium chloride enables the formation of more ordered 2D tin-based perovskite crystals oriented vertically. We use in-situ synchrotron-based grazing incident X-ray diffraction (GIXRD) to correlate the higher crystal orientation to the better device performance. We measured a maximum power conversion efficiency of >9%. Furthermore, we demonstrate that the phenyl ethyl ammonium chloride acts as a barrier layer at the surface of the crystals protecting the tin from the oxidation. Hence, this work paves the way for more efficient and stable lead-free perovskite solar cells.
关键词： phenyl ethyl ammonium chloride,photovoltaic material,crystal orientation,lead-free perovskite solar cells,oxidation of Sn2+,2D Ruddlesden-Popper tin-based halide perovskites,power conversion efficiency
更新于2025-09-23 15:21:01
-
Tailoring Component Interaction for Aira??Processed Efficient and Stable Alla??Inorganic Perovskite Photovoltaic
摘要： All-inorganic lead halide perovskites with potential stability improvement is promising candidate for optoelectronic applications. However, fundamental questions remain over the component interaction in the perovskite precursor solution due to the limitation of the most commonly used solvents of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). Here, we report a simple and very effective interaction tailoring strategy for all-inorganic CsPbI3-xBrx perovskites by involving ionic liquid solvent methylammonium acetate (MAAc). We found that C=O has strong interaction with lead (Pb2+) and the N-H…I hydrogen bonds formation are observed. The interaction enables the stable perovskite precursor solution and allows the high-quality production of pinhole-free, large grain size, and flat all-inorganic perovskite films by retarding the crystallization. With a one-step, without the necessity for antisolvent treatment, air-processing approach regardless of humidity, the corresponding photovoltaic cell exhibits a high efficiency of 17.10% along with long operation stability over 1500 h under continuous light illumination.
关键词： photovoltaic,component interaction,all-inorganic perovskites,stability,ionic liquid solvent
更新于2025-09-23 15:21:01
-
Mechanisms of LiF Interlayer Enhancements of Perovskite Light-Emitting Diodes
摘要： The use of LiF as a thin interlayer between the electron transport layer and cathode has played a pivotal role in remarkable advances in perovskite LEDs (PeLEDs); however, the mechanism behind the effect of LiF remains to be fully understood. Here we report a combined experimental and computational study from which we ascribe the benefits of a LiF interlayer to the migration of dissociated Li into the cathode and dissociated F into the anode. Electronic device simulations reveal that the former improves electron injection by lowering the Schottky barrier height, while the latter reduces the barrier width. These reduce turn-on voltage and improve current density and charge balance in LEDs. We fabricate PeLEDs with and without the LiF interlayer and link these materials and electronic phenomena to the device light-current-voltage characteristics. X-ray photoelectron spectroscopy obtained in sputter profiling of PeLEDs corroborates the dissociation of LiF.
关键词： LEDs,interface dipoles,metal-halide perovskites,photoelectron spectroscopy,band alignment
更新于2025-09-23 15:21:01
-
General Synthesis Principles for Ruddlesden-Popper Hybrid Perovskite Halides from a Dynamic Equilibrium
摘要： Two-dimensional (2D) Ruddlesden-Popper hybrid perovskites are a homologous series of compounds with the formula A’2An–1BnX3n+1 (A’ = bulky organic cation; A = small organic cation; B = Pb2+ or Sn2+, X = Cl–, Br–, I–; n is an integer) composed of inorganic octahedra layers separated by organic spacer cations. The octahedral layer thickness is modified by the stoichiometry of the A site cation, but limited methods exist for controlled and discriminating synthesis for all compositions. We report a general synthesis method and its principles that yield phase-pure 2D hybrid perovskites; the chemistry operates within a dynamic equilibrium established by the molar solubility of the compounds within the homologous series. A solvent-antisolvent (HI-acetic acid) pair and the common-ion effect provide selective control over the molar solubility to precipitate phase-pure compounds, as is supported by simple and predictive calculations. Here, this approach is demonstrated in detail with A’ = n-butylammonium, A = methylammonium, and n ≤ 3 and is applied to the synthesis and discovery of materials with other bulky ammonium cations (e.g., iso-butylammonium and benzylammonium).
关键词： dynamic equilibrium,Ruddlesden-Popper,molar solubility,common-ion effect,hybrid perovskites,solvent-antisolvent,synthesis
更新于2025-09-23 15:21:01
-
Photoluminescencea??Based Characterization of Halide Perovskites for Photovoltaics
摘要： Photoluminescence spectroscopy is a widely applied characterization technique for semiconductor materials in general and halide perovskite solar cell materials in particular. It can give direct information on the recombination kinetics and processes as well as the internal electrochemical potential of free charge carriers in single semiconductor layers, layer stacks with transport layers, and complete solar cells. The correct evaluation and interpretation of photoluminescence requires the consideration of proper excitation conditions, calibration and application of the appropriate approximations to the rather complex theory, which includes radiative recombination, non-radiative recombination, interface recombination, charge transfer, and photon recycling. In this article, an overview is given of the theory and application to specific halide perovskite compositions, illustrating the variables that should be considered when applying photoluminescence analysis in these materials.
关键词： halide perovskites,photoluminescence,photovoltaics,charge carriers,recombination kinetics
更新于2025-09-23 15:21:01
-
Role of PCBM in the Suppression of Hysteresis in Perovskite Solar Cells
摘要： The power conversion efficiency of inorganic–organic hybrid lead halide perovskite solar cells (PSCs) is approaching that of those made from single crystalline silicon; however, they still experience problems such as hysteresis and photo/electrical-field-induced degradation. Evidences consistently show that ionic migration is critical for these detrimental behaviors, but direct in-situ studies are still lacking to elucidate the respective kinetics. Three different PSCs incorporating phenyl-C61-butyric acid methyl ester (PCBM) and a polymerized form (PPCBM) is fabricated to clarify the function of fullerenes towards ionic migration in perovskites: 1) single perovskite layer, 2) perovskite/PCBM bilayer, 3) perovskite/PPCBM bilayer, where the fullerene molecules are covalently linked to a polymer backbone impeding fullerene inter-diffusion. By employing wide-field photoluminescence imaging microscopy, the migration of iodine ions/vacancies under an external electrical field is studied. The polymerized PPCBM layer barely suppresses ionic migration, whereas PCBM readily does. Temperature-dependent chronoamperometric measurements demonstrate the reduction of activation energy with the aid of PCBM and X-ray photoemission spectroscopy (XPS) measurements show that PCBM molecules are viable to diffuse into the perovskite layer and passivate iodine related defects. This passivation significantly reduces iodine ions/vacancies, leading to a reduction of built-in field modulation and interfacial barriers.
关键词： perovskites,ion migration,J–V curve hysteresis,PCBM
更新于2025-09-23 15:21:01
-
Surface Plasmon Resonance Effect Enhanced CsPbBr <sub/>3</sub> Inverse Opals for Higha??Performance Inorganic Perovskite Solar Cells
摘要： Although all-inorganic CsPbBr3 are considered an ideal candidate for inorganic perovskite solar cells (PSCs) owing to their outstanding thermal- and moisture-resistance, it still suffers from unfavorable charge transfer process and limited light harvesting ability. Herein, CsPbBr3 inverse opal (IO) films coupled with Au nanoparticles (NPs) are rationally designed, and PSCs based on Au-CsPbBr3 IO achieve a stabilized photoelectric conversion efficiency up to 8.08%. By selectively tuning IO pore diameter, the slow photon region of CsPbBr3 IO and localized surface plasmon resonance (SPR) region from Au NPs can be modulated to be overlapped to enhance the performance of inorganic CsPbBr3 PSCs. The synergetic effect devotes to light utilization and charge transfer process, resulting in an enhanced light absorption capability and suppressed recombination rate of photogenerated electron–hole pairs. The introduction of Au not only triggers SPR effect, but also enhances efficient separation/injection of charge carriers owing to the Schottky barriers. Furthermore, it is revealed that simultaneous effect from SPR and IO photon effect are conducive to reduce exciton binding energy, enhancing exciton dissociation efficiency and leading to significant increase in free carrier density. This work provides a rational strategy for plasmonic metal/semiconductor composite light-absorber for high-performance inorganic PSCs.
关键词： inverse opal,inorganic perovskites,Au nanoparticles,surface plasmon resonance,slow photon effects
更新于2025-09-23 15:21:01
-
Extrinsic Ion Distribution Induced Field Effect in CsPbIBr <sub/>2</sub> Perovskite Solar Cells
摘要： Excellent power conversion efficiency (PCE) and stability are the primary forces that propel the all-inorganic cesium-based halide perovskite solar cells (PSCs) toward commercialization. However, the intrinsic high density of trap state and internal nonradiative recombination of CsPbIBr2 perovskite film are the barriers that limit its development. In the present study, a facile additive strategy is introduced to fabricate highly efficient CsPbIBr2 PSCs by incorporating sulfamic acid sodium salt (SAS) into the perovskite layer. The additive can control the crystallization behaviors and optimize morphology, as well as effectively passivate defects in the bulk perovskite film, thereby resulting in a high-quality perovskite. In addition, SAS in perovskite has possibly introduced an additional internal electric field effect that favors electron transport and injection due to inhomogeneous ion distribution. A champion PCE of 10.57% (steady-output efficiency is 9.99%) is achieved under 1 Sun illumination, which surpasses that of the contrast sample by 16.84%. The modified perovskite film also exhibits improved moisture stability. The unencapsulated device maintains over 80% initial PCE after aging for 198 h in air. The results provide a suitable additive for inorganic perovskite and introduce a new conjecture to explain the function of additives in PSCs more rationally.
关键词： sulfamic acid sodium,additive engineering,inorganic perovskites,perovskite solar cells,moisture stability
更新于2025-09-23 15:21:01