High-performance and stable CsPbBr3 light-emitting diodes based on polymer additive treatment

Because of their high efficiency and sharp emission, perovskite light-emitting diodes are a promising candidate for next-generation lighting techniques. However, the relatively poor stability of perovskite light-emitting diodes lowers their utility. Therefore, a highly stable perovskite light-emitting diode has to be developed to meet the commercial demand. Herein, we report a highly stable CsPbBr₃ light-emitting diode via simple polymer treatment. The addition of 2-methyl-2-oxazoline in perovskite film assists the formation of CsPbBr₃ nanocrystals, improving the quality and photoluminescence property of perovskite film. Based on such CsPbBr₃ nanocrystals and polymer hybrid film, our device presents a high external quantum efficiency and luminance of around 3.0% and 16 648 cd m⁻², respectively. Moreover, an excellent device half-lifetime of more than 2.4 hours has been achieved, under continuous operation at a relatively high initial luminance of 1000 cd m⁻², representing one of the most stable PeLEDs operated at such high initial luminance.

The 2-methyl-2-oxazoline additive induced the formation of high-quality CsPbBr₃ nanocrystals and a stable PeLED with a half-lifetime of 2.4 hours at high initial luminance of 1000 cd m⁻² was demonstrated, representing one of the most stable PeLEDs.     

Improved photoelectric performance of all-inorganic perovskite through different additives for green light-emitting diodes

The exceptional optical and electronic properties of all-inorganic cesium lead bromide (CsPbBr₃) perovskite make it an ideal new optoelectronic material, but low surface coverage limits its performance. The morphological characteristics of thin films have a great influence on the performance of perovskite light emitting diodes, especially at low coverage, and an inhomogeneous surface will lead to current leakage. To tackle this problem, the widespread adoption of composite layers including polymers poly(ethylene oxide) (PEO) and organic insulating poly(vinylpyrrolidone) (PVP) and all-inorganic perovskites is an effective way to increase the surface coverage and uniformity of perovskite films and improve the performance of perovskite light emitting devices. In our work, the perovskite thin films are investigated by using PEO and PVP dual additives, and the optimized CsPbBr₃–PEO–PVP LED with maximum luminance, current efficiency, and external quantum efficiency of 2353 cd m⁻² (at 7.2 V), 2.14 cd A⁻¹ (at 6.5 V) and 0.85% (at 6.5 V) was obtained. This work indicates that the method of using additives is not only the key to enhancing the quality of perovskite thin film, but also the key to achieving a higher performance perovskite LED.

Improving the performance of all-inorganic CsPbBr₃–PEO–PVP-based LEDs with the structure of ITO/PEDOT:PSS/Perovskite/TPBI/LiF/Al.     

A pressure-assisted annealing method for high quality CsPbBr3 film deposited by sequential thermal evaporation

All-inorganic CsPbBr₃ perovskite solar cells have triggered incredible interest owing to their superior stability, especially under high temperature conditions. Different from the organic–inorganic hybrid perovskites, inorganic CsPbBr₃ perovskite always need a high annealing temperature for the formation of a cubic phase. Generally, the higher temperature (over 300 °C) and longer annealing time will promote the growth of CsPbBr₃, resulting in larger grain sizes and lower trap density in the crystals. However, CsPbBr₃ perovskite can also be damaged by excessive annealing temperature (∼350 °C) and time, since PbBr₂ only has a melting temperature close to 357 °C. To address this issue, herein, we developed a novel pressure-assisted annealing method to prevent the sublimation of PbBr₂ at high temperature. The CsPbBr₃ films were firstly deposited by sequential thermal evaporation, and then annealed at 335 °C in an alloy pressure vessel. By controlling the pressure of the vessel, we obtained CsPbBr₃ films with various morphologies. At normal atmospheric pressure, the as-prepared CsPbBr₃ film exhibited small grain sizes and was full of pinholes. With the increase of annealing pressure, the grain sizes of the film showed a significant increasing trend, and the pinholes gradually vanished. When the pressure value came to 10 MPa, compact and uniform CsPbBr₃ films with large grain sizes were obtained. Based on these films, CsPbBr₃ perovskite solar cells with FTO/compact-TiO₂/CsPbBr₃/carbon architecture achieved a champion power conversion efficiency of 7.22%.

Pressure-assisted annealing method for the preparation of high-quality CsPbBr₃ perovskite films.     

Synthesis and model simulation of the hexagonal to circular transition of perovskite cesium lead halide nanosheets by rapidly changing the temperature

Lead halide perovskites have emerged as promising optoelectronic materials due to their excellent efficiencies in photovoltaic and light-emitting applications. CsPbBr₃ is a kind of all-inorganic perovskite that exhibits higher stability. Here, we report the synthesis of hexagonal and circular all-inorganic CsPbBr₃ perovskite nanoplates by changing the reaction temperature. As time goes on, the different reaction temperatures play an important role in determining the shape and size. We use first-principles to explicate the formation of hexagonal nanoplates. Meanwhile, a model is built and the calculation of the properties is conducted. In brief, a method to directly and conveniently synthesize all-inorganic CsPbBr₃ is proposed.

Lead halide perovskites have emerged as promising optoelectronic materials due to their excellent efficiencies in photovoltaic and light-emitting applications.     

Interface engineering for gain perovskite photodetectors with extremely high external quantum efficiency

Efficient CH₃NH₃PbI₃ photodetectors (PDs) with an extremely high gain of the maximum external quantum efficiency (EQE) of 140 000% within the ultraviolet region to the near infrared region (NIR) and an extremely high responsivity (R) under a low bias of −5 V were successfully fabricated. The fabricated devices manifested outstanding environmental stability with only 10% degradation of EQE after being exposed to air for 24 h. These obtained results indicate the promising potential of perovskite PDs for visible light communication applications.

Efficient CH₃NH₃PbI₃ photodetectors (PDs) with an extremely high gain of the maximum external quantum efficiency (EQE) of 140 000% within the ultraviolet region to the near infrared region (NIR) and an extremely high responsivity (R) under a low bias of −5 V were successfully fabricated.     

Cs4PbBr6/CsPbBr3 perovskite composites for WLEDs: pure white,high luminous efficiency and tunable color temperature

Cs₄PbBr₆/CsPbBr₃ perovskite composites are fabricated by room-temperature one-pot mixing synthesis, which is short in time, free from inert gases and delivers a high product yield. Temperature-dependent photoluminescence shows that a larger exciton binding energy of 291.1 meV exhibits better thermal stability compared with that of pure Cs₄PbBr₆ and CsPbBr₃ materials. The CIE chromaticity coordinates (0.1380, 0.7236) of green LEDs designed with Cs₄PbBr₆/CsPbBr₃ perovskite composites show almost no variation under driving current changing from 5 to 30 mA. Furthermore, the ground Cs₄PbBr₆/CsPbBr₃ perovskite composites mixed with red emitting K₂SiF₆:Mn⁴⁺ phosphor are dropped and casted on a blue-emitting InGaN chip. The white light emitting diodes (WLEDs) are presented, which have good luminous efficiency of 65.33 lm W⁻¹ at 20 mA, a correlated color temperature of 5190 K, and the white gamut with chromaticity coordinate of (0.3392, 0.3336). According to the state of art, these excellent characteristics observed are much superior to the reported results of conventional perovskite-based WLEDs, which demonstrate the immense potential and great prospect of Cs₄PbBr₆/CsPbBr₃ perovskite composites to replace conventional phosphors in lighting devices.

WLED devices are designed with high luminous efficiency of 65.33 lm W⁻¹ and excellent CIE chromaticity coordinates of (0.3392, 0.3336). The properties of material and the luminous performance of device are calculated and discussed comprehensively.     

In situ construction of a Te/CsPbBr3 heterojunction for self-powered photodetector

In this study, CsPbBr₃ particles were prepared by a simple solvent evaporation method in ambient environment; the p–n heterojunction formed by CsPbBr₃ particles on the surface of a single long Te wire was used to construct a high-performance Te/CsPbBr₃ photodetector. Compared with CsPbBr₃ PDs, the Te/CsPbBr₃ photodetector showed improved photocurrent, and exhibited characteristics of excellent self-powered performance, broad-spectrum response (UV-visible), and ultra-fast response speed (t_rise = 0.09 ms). In addition, under zero bias and upon 540 nm light irradiation, the device had good responsivity (0.35 mA W⁻¹), high photosensitivity (up to 100 on/off ratio), and a detectivity of 1.42 × 10¹⁰ Jones. This study provides insight into the possibility of manufacturing high-performance self-powered photodetectors through a simple in situ construction of heterojunctions.

In this study, CsPbBr₃ particles were prepared by a simple solvent evaporation method in ambient environment; the p–n heterojunction formed by CsPbBr₃ particles on the surface of a single long Te wire was used to construct a high-performance Te/CsPbBr₃ photodetector.     

Direct deposition of Sn-doped CsPbBr3 perovskite for efficient solar cell application

All inorganic carbon-based planar perovskites, particularly CsPbBr₃, have attracted considerable attention due to their excellent stability against oxygen, moisture, and heat for photovoltaic utilization. However, the power conversion efficiency of carbon-based planar CsPbBr₃ perovskite solar cells is mostly low, primarily because of the inferior film quality with undesirable crystallization and narrow light absorbance ranges. Herein, we develop a novel direct deposition approach combined with Sn doping to achieve highly efficient and stable carbon-based Sn-doped CsPbBr₃ perovskite solar cells. Mass-scale Sn ion-doped CsPbBr₃ perovskite powder was effectively synthesized and characterized via a facile strategy by adding hydrohalic acid in the CsBr, PbBr₂ and SnBr₂ precursor in a dimethyl sulfoxide solution. Moreover, using the as-synthesized CsPbBr₃ and Sn-doped CsPbBr₃ perovskite powder, PSCs were obtained via effective direct thermal evaporation. A smooth, constant and pinhole-free perovskite film was achieved with a configuration of FTO/TiO₂/Sn:CsPbBr₃/carbon. PSCs based on Sn:CsPbBr₃ as an absorber and carbon as the HTM achieved an impressive power conversion efficiency of 8.95% compared to 6.87% for undoped CsPbBr₃; moreover, it displayed admirable stability in an open-air atmosphere for an operational period of about 720 h without a noticeable negative result. The introduction of the Sn ion may advance the interface extraction of charge between the electric transport layer to the absorber layer and absorber to the carbon electrode. Accordingly, the Sn ion doping on CsPbBr₃ during the synthesis phase and the direct evaporation paves a novel approach for intended photovoltaic applications.

All inorganic carbon-based planar perovskites, particularly CsPbBr₃, have attracted considerable attention due to their excellent stability against oxygen, moisture, and heat for photovoltaic utilization.     

Surface plasmon coupling regulated CsPbBr3 perovskite lasers in a metal–insulator–semiconductor structure

A strong coupling effect often occurs between a metal and semiconductor, so micro/nano-lasers based on surface plasmons can break through the optical diffraction limit and realize unprecedented linear and nonlinear enhancement of optical processes. Hence, metal–insulator–semiconductor (M–I–S) structures based on perovskite materials were explored to design optoelectronic devices. Herein, we constructed an Ag/SiO₂/CsPbBr₃ hybrid structure to generate surface plasmon coupled emission between the metal and CsPbBr₃ perovskite. Combined with experimental characterization and COMSOL Multiphysics software simulations, the best enhancement for CsPbBr₃ radiative recombination efficiencies can be achieved with a 10 nm-thickness of the SiO₂ layer and 80 nm-thickness of the Ag metal film, further verified by optimizing the thickness of the SiO₂ layer above the Ag metal film. In this state, the laser threshold can be as low as 0.138 μW with a quality (Q) factor of up to 3907 under optical pumping, which demonstrate a significant step toward practical applications in biological technology, chemical identification, and optical interconnections of information transmission.

A strong coupling effect often occurs between a metal and semiconductor, so micro/nano-lasers based on surface plasmons can break through the optical diffraction limit and realize unprecedented linear and nonlinear enhancement of optical processes.     

Influence of the rate of radiation energy on the charge-carrier kinetics application of all-inorganic CsPbBr3 perovskite nanocrystals

In the field of optoelectronics, all-inorganic CsPbBr₃ perovskite nanocrystals (PNCs) have gained significant interest on account of their superb processability and ultra-high stability among all the counterparts. In this study, we conducted an in-depth analysis of CsPbBr₃ PNCs using joint transient optical spectroscopies (time-resolved photoluminescence and ultrafast transient absorption) in a very comprehensive manner. In order to understand the in-depth analysis of excited-state kinetics, the transient absorption spectroscopy has been performed. The structure of interest of CsPbBr₃ PNCs was subjected to the rates of the radiation energy of 0.10 mW (κ_r/κ_nr = ∼0.62) and 0.30 mW (κ_r/κ_nr = ∼0.64). With the rate of radiation energy 0.30 mW, it was observed that there was a significant increase in hot carrier relaxation together with high radiative recombination, resulting in a decrease in charge trappings. Herein, we demonstrate that the tuning of the rate of radiation energies helps to understand the charge-carrier kinetics of CsPbBr₃ PNCs, which would thus improve the manufacturing of efficient photovoltaic devices.

A mechanistic framework for hot carrier cooling process in CsPbBr₃ PNC is depicted via transient absorption spectroscopy.     

Stable green and red dual-color emission in all-inorganic halide-mixed perovskite single microsheets

Recently, all-inorganic perovskites have attracted tremendous attention due to their excellent optoelectronic properties and extensive potential applications. However, these perovskites usually show a single emission wavelength because of the high ionic migration. Herein, we synthesized all-inorganic halide-mixed perovskite CsPbBr_xI_3−x microsheets with high crystal quality using the anti-solvent solution method and observed extraordinary green and red dual-color emission in single CsPbBr_xI_3−x microsheets. Power dependent PL spectra reveal excitonic and defect related recombination features of CsPbBr₃ and CsPbI₃ for the green and red emission. Temperature dependent PL spectra indicated a distinctive exciton–phonon coupling strength in CsPbBr_xI_3−x microsheets compared with pure CsPbBr₃ and CsPbI₃. The PL dynamics showing longer emission lifetime further confirmed this conclusion. Our work not only provides a novel strategy to produce stable dual-color emission integration, but also promotes the fundamental insight into the emission dynamics and exciton/free carrier related photophysics in all-inorganic halide-mixed perovskites.

PL spectra with stable green and red dual-colors emission were observed in the single CsPbBr_xI_3−x microsheet.     

A high-precision,template-assisted,anisotropic wet etching method for fabricating perovskite microstructure arrays

Cesium lead-halide (CsPbX₃; X = Cl, Br, I) perovskite microstructure arrays have become the basis for laser array applications, due to their outstanding spectral coherence, low threshold, and wideband tunability. Furthermore, the common fabrication methods for these arrays have the limitation to achieve both tailored design and high resolution simultaneously. Herein, we report a high-precision, template-assisted, wet etching (TAWE) method for the preparation of perovskite microstructure arrays. This method possesses the advantages of flexible design, controllable size, and ultrahigh accuracy (the resolution can reach 1 μm or higher). A 20 × 20 inverted pyramid array with a diameter of 3 μm and a period of 4 μm was fabricated using this method. CsPbBr₃ perovskite quantum dots fabricated by means of hot injection were filled into the inverted pyramid array via spin-coating and pumped using a laser with a wavelength of 400 nm. The lasing characteristics of the array were then measured and analyzed; the threshold was measured to be 37.6 μJ cm⁻², and the full width at half maximum of the amplified spontaneous emission spectrum was found to be about 4.7 nm. These results demonstrate that perovskite microstructure arrays prepared via this method have potential applications in laser arrays.

A template-assisted wet etching method for the preparation of perovskite micro-structure array is proposed. This method has a superiority of flexible graph design, controllable size and high precision.     

Carbon electrode engineering for high efficiency all-inorganic perovskite solar cells

Carbon-based inorganic perovskite solar cells (PSCs) have demonstrated an excellent performance in the field of photovoltaics owing to their simple fabrication techniques, low-cost and superior stability. Despite the lower efficiency of devices with a carbon electrode compared with the conventional structure, the potential applications in large scale have attracted increasing attention. Herein, we employ a mixed carbon electrode inorganic PSC by incorporating one-dimensional structure carbon nanotubes (CNTs) and two-dimensional Ti₃C₂-MXene nanosheets into a commercial carbon paste. This mixed carbon electrode, which is different from the pure carbon electrode in showing a point-to-point contact, provides a network structure and multi-dimensional charge transfer path, which effectively increases the conductivity of the carbon electrode and carriers transport. A respectable power conversion efficiency of 7.09% is obtained through carbon/CNT/MXene mixed electrode in CsPbBr₃-based solar cells.

A carbon/CNT/MXene mixed electrode in CsPbBr₃ solar cells provides a network structure and multi-dimensional charge transfer path, which effectively increases the conductivity of the carbon electrode and carriers transport.     

Rapid synthesis of cesium lead halide perovskite nanocrystals by l-lysine assisted solid-phase reaction at room temperature

Nowadays, there are many ways to obtain cesium lead halide perovskite nanocrystals. In addition to the synthesis methods carried out in solution, the solid-phase synthesis was reported involving grinding and milling. In this paper, we synthesized luminescent CsPbBr₃/Cs₄PbBr₆ perovskite nanocrystals (PNCs) by three solid-phase synthesis methods (grinding, knocking, stirring) using l-lysine as a ligand. This is the first attempt to use an amino acid for assisting the solid phase synthesis of perovskite and to study the difference in the products obtained by the three solid phase synthesis methods. The results show that the productivity of the solid-phase synthesis methods can be greatly improved by adding l-lysine and the perovskites obtained by the methods are more resistant to water due to the addition of l-lysine. The simplicity of the synthesis process expanded the use of solid-phase synthesis to obtain more perovskites and provided potential applications of perovskite in analytical detection and sensing in aqueous solution.

By comparing three different solid-phase reactions of perovskite powder synthesized using lysine, the reaction process and properties were studied.     

A simple multiple centrifugation method for large-area homogeneous perovskite CsPbBr3 films with optical lasing

Large scale cesium lead-halide (CsPbX₃, X = Cl, Br, and I) perovskite films have become the basis of laser applications. Common fabrication methods such as spin-coating and thermal evaporation have a trade-off between high quality and low cost. Herein, we reported a facile method for preparing a large area homogeneous perovskite CsPbBr₃ film via a multiple centrifugal deposition and solvent annealing (MCDSA) method. This method is superior because it can control the thickness (180 nm to 880 nm) of the film, ensure the film is crack and pinhole free, has a large area (2.5 cm × 2.5 cm), and has a low surface roughness (a root mean square of 32 nm). Multiple times of centrifugation and solvent annealing in the MCDSA method are key to improving the quality of the film as well as the laser performance. With increased centrifugation cycles from one to four, the thickness of the film increases from 180 nm to 880 nm, leading to a decrease in the laser threshold from 18.1 μJ cm⁻² to 14.2 μJ cm⁻² and an increase in the gain coefficient from 78.5 cm⁻¹ to 112.7 cm⁻¹. When solvent annealing is employed, the gain coefficient is further increased to 122.7 cm⁻¹.

Large scale cesium lead-halide (CsPbX₃, X = Cl, Br, and I) perovskite films have become the basis of laser applications.     

A facile method for preparing Yb3+-doped perovskite nanocrystals with ultra-stable near-infrared light emission

Colloidal all-inorganic cesium lead halide (CsPbX₃, X = Cl, Br, I) nanocrystals (NCs) are very important optoelectronic materials and have been successfully utilized as bright light sources and high efficiency photovoltaics due to their facile solution processability. Recently, rare-earth dopants have opened a new pathway for lead halide perovskite NCs for applications in near-infrared wave bands. However, these materials still suffer from serious environmental instability. In this study, we have successfully developed a facile method for fabricating all-inorganic SiO₂-encapsulated Yb³⁺-doped CsPbBr₃ NCs by slowly hydrolyzing the organosilicon precursor in situ. Experimental results showed that the Yb³⁺ ions were uniformly distributed in the NCs, and the whole NCs were completely encapsulated by a dense SiO₂ layer. The as-prepared SiO₂-encapsulated NCs can emit a strong near-infrared (985 nm) photoluminescence, which originates from the intrinsic luminescence of Yb³⁺ in the NCs, pumped by the perovskite host NCs. Meanwhile, the SiO₂-encapsulated NCs possessed excellent high PLQYs, narrow FWHM, and excellent environmental stability under a room atmosphere for over 15 days. We anticipate that this work will be helpful for promoting the optical properties and environmental stability of perovskite NCs and expanding their practical applications to near infrared photodetectors and other optoelectronic devices.

A facile method for fabricating CsPbBr₃:Yb³⁺@SiO₂ NCs which guarantees high PLQY and excellent stability at the same time.     

Composition-tuned MAPbBr3 nanoparticles with addition of Cs+ cations for improved photoluminescence

Hybrid organic–inorganic lead halide perovskite nanoparticles are promising candidates for optoelectronic applications. This investigation describes the structural and optical properties of MA_xCs_1−xPbBr₃ mixed cation colloidal nanoparticles spanning the complete compositional range of Cs substitution. A monotonic progression in the cubic lattice parameter (a) with changes in the Cs⁺ content confirmed the formation of mixed cation materials. More importantly, time-resolved photoluminescence (TRPL) revealed the optimized 13 mol% Cs nanoparticle composition exhibits the longest charge carrier lifetime and enhancement in radiative pathways. This sample also showed the highest photoluminescence quantum yield (PLQY) of ∼88% and displays ∼100% improvement in the PLQY of pure MAPbBr₃ and CsPbBr₃. Prototype LEDs fabricated from MA_0.87Cs_0.13PbBr₃ were demonstrated.

Structural and optical properties of MA_xCs_1−xPbBr₃ mixed cation colloidal nanoparticles with 13 mol% Cs composition exhibiting the longest charge carrier lifetime and enhancement in radiative pathways.     

Highly bright perovskite light-emitting diodes based on quasi-2D perovskite film through synergetic solvent engineering

Recently, quasi-two dimensional (2D) perovskites have attracted great interest as they can be facilely fabricated and yield high photoluminescence quantum yield. However, the luminance and the efficiency of perovskite light-emitting diodes (PeLEDs) based on quasi-2D perovskites are limited by the carrier transport and the crystallization properties of the quasi-2D perovskite films. Herein, a synergetic solvent engineering approach is proposed to improve the crystallinity and the carrier transport by optimizing the film morphology of the quasi-2D perovskite films. Consequently, the maximum luminance of green PeLEDs based on quasi-2D PEA₂ (MAPbBr₃)₂PbBr₄ perovskite is dramatically enhanced from 4000 cd m⁻² to 18 000 cd m⁻² and the current efficiency increases from 3.40 cd A⁻¹ to 8.74 cd A⁻¹. This work provides a promising way to control the morphology and the crystallinity properties of quasi-2D perovskite films for high-performance optoelectronic devices.

A synergetic solvent engineering approach to improve crystallinity and carrier transport, by optimizing film morphology of the quasi-2D perovskite films.     

Highly efficient radiative recombination in intrinsically zero-dimensional perovskite micro-crystals prepared by thermally-assisted solution-phase synthesis

Zero-dimensional (0D) quantum confinement can be achieved in perovskite materials by the confinement of electron and hole states to single PbX₆⁴⁻ perovskite octahedra. In this work, 0D perovskite (Cs₄PbBr₆) micro-crystals were prepared by a simple thermally-assisted solution method and thoroughly characterized. The micro-crystals show a high level of crystallinity and a high photoluminescence quantum yield of 45%. The radiative recombination coefficient of the 0D perovskite micro-crystals, 1.5 × 10⁻⁸ s⁻¹ cm³, is two orders of magnitude higher than that of typical three-dimensional perovskite and is likely a strong contributing factor to the high emission efficiency of 0D perovskite materials. Temperature dependent luminescence measurements provide insight into the role of thermally-activated trap states. Spatially resolved measurements on single 0D perovskite micro-crystals reveal uniform photoluminescence intensity and emission decay behaviour suggesting the solution-based fabrication method yields a high-quality and homogenous single-crystal material. Such uniform emission reflects the intrinsic 0D nature of the material, which may be beneficial to device applications.

0D Cs₄PbBr₆ perovskite microcrystals exhibit a radiative recombination coefficient two orders of magnitude higher than typical 3D perovskite.     

CH3NH3Pb1−xEuxI3 mixed halide perovskite for hybrid solar cells: the impact of divalent europium doping on efficiency and stability

The crucial role of the impact of divalent europium doping in perovskite solar cells is investigated in this work. We selected europium (Eu²⁺, 117 pm) to replace lead (Pb²⁺, 119 pm) because their ion radii are really comparable. This appropriate substitution has shown great potential to achieve high stability and enhance the power conversion efficiency of the solar cells. Through adjusting the doping concentration of europium, the perovskite solar cells corresponding average efficiency greatly increased. Furthermore, compared with the CH₃NH₃PbI₃ perovskite film, the attenuation of power conversion efficiency of europium doped perovskite film slowed down 4.7 times at room temperature. Therefore, we put forward a useful method for the optimization of organic–inorganic perovskite solar cells.

The crucial role of the impact of divalent europium doping in perovskite solar cells is investigated in this work.