Phenylethylammonium Research Articles

Unveiling the impact of organic cation passivation on structural and optoelectronic properties of two-dimensional perovskites thin films

Several organic cations have been used to passivate perovskite films; however, selecting the optimal cation remains challenging. In this work, we carried out density functional theory calculations to understand the effects induced by 17 different organic cations on the passivation (P-cations) of thin two-dimensional P2 (MAn−1)PbnI3n+1 perovskites films, where n=1 and 2. We found that the interactions between different types of P-cations and the inorganic slab affect the length and angles of the bonds within the inorganic framework (PbI6-octahedra). In general, the binding mechanism includes the interactions of organic cations with the inorganic framework, which leads to the accumulation of electron density within the halides, indicative of Brønsted–Lowry acid–base interactions. Oxygenated groups facilitate additional H-bond formation through -OH and -COOH groups, promoting the localization of the electron density between layers and improving the energetic stability of the system. Based on the results and analysis, we found that three P-cations might have higher potential for real-life applications, namely 4-fluorophenylethylammonium (FPEA), phenylethylammonium (PEA) and butylammonium (BtA).

Elucidating phonon dephasing mechanisms in layered perovskites with coherent Raman spectroscopies.

Organic-inorganic hybrid perovskite quantum wells exhibit electronic structures with properties intermediate between those of inorganic semiconductors and molecular crystals. In these systems, periodic layers of organic spacer molecules occupy the interstitial spaces between perovskite sheets, thereby confining electronic excitations to two dimensions. Here, we investigate spectroscopic line broadening mechanisms for phonons coupled to excitons in lead-iodide layered perovskites with phenyl ethyl ammonium (PEA) and azobenzene ethyl ammonium (AzoEA) spacer cations. Using a modified Elliot line shape analysis for the absorbance and photoluminescence spectra, polaron binding energies of 11.2 and 17.5meV are calculated for (PEA)2PbI4 and (AzoEA)2PbI4, respectively. To determine whether the polaron stabilization processes influence the dephasing mechanisms of coupled phonons, five-pulse coherent Raman spectroscopies are applied to the two systems under electronically resonant conditions. The prominence of inhomogeneous line broadening mechanisms detected in (AzoEA)2PbI4 suggests that thermal fluctuations involving the deformable organic phase broaden the distributions of phonon frequencies within the quantum wells. In addition, our data indicate that polaron stabilization primarily involves photoinduced reorganization of the organic phases for both systems, whereas the impulsively excited phonons represent less than 10% of the total polaron binding energy. The signal generation mechanisms associated with our fifth-order coherent Raman experiments are explored with a perturbative model in which cumulant expansions are used to account for time-coincident vibrational dephasing and polaron stabilization processes.

Ligand Homogenized Br-I Wide-Bandgap Perovskites for Efficient NiOx-Based Inverted Semitransparent and Tandem Solar Cells.

Phase heterogeneity of bromine-iodine (Br-I) mixed wide-bandgap (WBG) perovskites has detrimental effects on solar cell performance and stability. Here, we report a heterointerface anchoring strategy to homogenize the Br-I distribution and mitigate the segregation of Br-rich WBG-perovskite phases. We find that methoxy-substituted phenyl ethylammonium (x-MeOPEA+) ligands not only contribute to the crystal growth with vertical orientation but also promote halide homogenization and defect passivation near the buried perovskite/hole transport layer (HTL) interface as well as reduce trap-mediated recombination. Based on improvements in WBG-perovskite homogeneity and heterointerface contacts, NiOx-based opaque WBG-perovskite solar cells (WBG-PSCs) achieved impressive open-circuit voltage (Voc) and fill factor (FF) values of 1.22 V and 83%, respectively. Moreover, semitransparent WBG-PSCs exhibit a PCE of 18.5% (15.4% for the IZO front side) and a high FF of 80.7% (79.4% for the IZO front side) for a designated illumination area (da) of 0.12 cm2. Such a strategy further enables 24.3%-efficient two-terminal perovskite/silicon (double-polished) tandem solar cells (da of 1.159 cm2) with a high Voc of over 1.90 V. The tandem devices also show high operational stability over 1000 h during T90 lifetime measurements.

Passivating A-Site and X-Site Vacancies Simultaneously via N-Heterocyclic Amines for Efficient Cs2AgBiBr6 Solar Cells.

To address the toxicity and stability issues of traditional lead halide perovskite solar cells (PSCs), the development of lead-free PSCs, such as Cs2AgBiBr6 solar cells, is of great significance. However, due to the low defect formation energy of Cs2AgBiBr6, a large number of vacancies, including A-site vacancies and X-site vacancies, form during the fabrication process of the Cs2AgBiBr6 film, which seriously damage the performance of the devices. The traditional phenylethylammonium (PEA) cation, mainly focusing on passivating A-site vacancies, is incapable of reducing X-site vacancies and so results in a limited performance improvement in Cs2AgBiBr6 solar cells. Herein, inspired by the capability of the Lewis base to coordinate with metal cations, a series of N-heterocyclic amines are introduced to serve as a dual-site passivator, reducing A-site and X-site vacancies at the same time. The highest power conversion efficiency of modified Cs2AgBiBr6 solar cells has been increased 36% from 1.10 to 1.50%. Further investigation reveals that the higher electron density of additives would lead to a stronger interaction with metal cations like Ag+ and Bi3+, thus reducing more X-site defects and improving carrier dynamics. Our work provides a strategy for passivating perovskite with various kinds of defects and reveals the connection between the coordination capability of additives and device performance enhancement, which could be instructive in improving the performance of lead-free PSCs.

Insights into the Growth Orientation and Phase Stability of Chemical-Vapor-Deposited Two-Dimensional Hybrid Halide Perovskite Films.

Chemical vapor deposition (CVD) offers a large-area, scalable, and conformal growth of perovskite thin films without the use of solvents. Low-dimensional organic-inorganic halide perovskites, with alternating layers of organic spacer groups and inorganic perovskite layers, are promising for enhancing the stability of optoelectronic devices. Moreover, their multiple quantum-well structures provide a powerful platform for tuning excitonic physics. In this work, we show that the CVD process is conducive to the growth of 2D hybrid halide perovskite films. Using butylammonium (BA) and phenylethylammonium (PEA) cations, the growth parameters of BA2PbI4 and PEA2PbI4 and mixed halide perovskite films were first optimized. These films are characterized by well-defined grain boundaries and display characteristic absorption and emission features of the 2D quantum wells. X-ray diffraction (XRD) and a noninteger dimensionality model of the absorption spectrum provide insights into the orientation of the crystalline planes. Unlike BA2PbI4, temperature-dependent photoluminescence measurements from PEA2PbI4 show a single excitonic peak throughout the temperature range from 20 to 350 K, highlighting the lack of defect states. These results further corroborate the temperature-dependent synchrotron-based XRD results. Furthermore, the nonlinear optical properties of the CVD-grown perovskite films are investigated, and a high third harmonic generation efficiency is observed.

Tailoring Interlayer Charge Transfer Dynamics in 2D Perovskites with Electroactive Spacer Molecules.

The family of hybrid organic-inorganic lead-halide perovskites are the subject of intense interest for optoelectronic applications, from light-emitting diodes to photovoltaics to X-ray detectors. Due to the inert nature of most organic molecules, the inorganic sublattice generally dominates the electronic structure and therefore the optoelectronic properties of perovskites. Here, we use optically and electronically active carbazole-based Cz-Ci molecules, where Ci indicates an alkylammonium chain and i indicates the number of CH2 units in the chain, varying from 3 to 5, as cations in the two-dimensional (2D) perovskite structure. By investigating the photophysics and charge transport characteristics of (Cz-Ci)2PbI4, we demonstrate a tunable electronic coupling between the inorganic lead-halide and organic layers. The strongest interlayer electronic coupling was found for (Cz-C3)2PbI4, where photothermal deflection spectroscopy results remarkably reveal an organic-inorganic charge transfer state. Ultrafast transient absorption spectroscopy measurements demonstrate ultrafast hole transfer from the photoexcited lead-halide layer to the Cz-Ci molecules, the efficiency of which increases by varying the chain length from i = 5 to i = 3. The charge transfer results in long-lived carriers (10-100 ns) and quenched emission, in stark contrast to the fast (sub-ns) and efficient radiative decay of bound excitons in the more conventional 2D perovskite (PEA)2PbI4, in which phenylethylammonium (PEA) acts as an inert spacer. Electrical charge transport measurements further support enhanced interlayer coupling, showing increased out-of-plane carrier mobility from i = 5 to i = 3. This study paves the way for the rational design of 2D perovskites with combined inorganic-organic electronic properties through the wide range of functionalities available in the world of organics.

Optimization of open circuit voltage and stability of Sn–Pb mixed perovskite solar cells by phenyl–ethyl ammonium bromide

Optimization of open circuit voltage and stability of Sn–Pb mixed perovskite solar cells by phenyl–ethyl ammonium bromide

Evaluation of time dependent mechanical properties through nanoindentation of different compositions of 2D Ruddlesden Popper and 3D lead halide perovskites

Hybrid organic-inorganic perovskite (HOIPs) films' simplicity in manufacturing, both in solution and at low temperatures, foresees its application in deformable technologies including flexible photovoltaics, sensors and displays. The next generation of flexible optoelectronic devices may be possible owing to the special characteristics of hybrid organic-inorganic perovskites (HOIPs). However, it is necessary to have a thorough knowledge of the mechanical response of hybrid organic-inorganic perovskites(HOIPs) to dynamic strain to successfully use them in deformable devices. In the current study, a range of perovskites: 3D, butylammonium(BA) based 2D and quasi-2D, phenylethylammonium(PEA) based 2D and quasi-2D perovskite have been fabricated with particle sizes ranging in 5–10 nm as found using TEM. The nanoindentation creep and stress relaxation experiments prove the time and rate-dependent mechanical properties of this 2D, quasi-2D, and 3D HOIPs crystal though varying in their magnitudes. We observe that the 3D as well as BA based perovskite show strain rate sensitivity whereas PEA based perovskite samples were relatively insensitive towards the rate of loading. Propagation and interaction of dislocation are much more difficult in PEA-based perovskite, which has a triclinic crystal structure and are less symmetrical as compared to the BA based and 3D perovskite orthorhombic and tetragonal structure respectively. The knowledge offered by this work is crucial for creating perovskite devices that can endure mechanical deformations.

High‐Performance Perovskite Solar Cells with Low Open‐Circuit Voltage Loss and Excellent Stability after p‐F‐PEAI Posttreatment

Photoelectric properties of perovskite solar cells (PSCs) are closely linked to defects on the surface of perovskite in the preparation process, which have a significant impact on the open‐circuit voltage (VOC) of devices. It is necessary for high‐performance PSCs to suppress the non‐radiative recombination at the interface and improve the charge transfer. Herein, phenylethyl ammonium iodide containing fluorine (p‐F‐PEAI) is utilized to treat the perovskite film, which can optimize the energy‐level alignment between perovskite layer and hole‐transport layer to promote charge transfer and reduce non‐radiative recombination by passivating interface defects and inhibiting the generation of Pb0. The introduction of fluoride can enhance the electropositivity of −NH3+ to obtain excellent passivation and moisture resistance. The p‐F‐PEAI‐modified PSCs achieve a superior power conversion efficiency of 22.56% with remarkable VOC (1.20 V) and maintain 96% of the initial optimal value after 1000 h without encapsulation.

Effect of Acidic Strength of Surface Ligands on the Carrier Relaxation Dynamics of Hybrid Perovskite Nanocrystals.

Perovskite nanocrystals (PeNCs) are known for their use in numerous optoelectronic applications. Surface ligands are critical for passivating surface defects to enhance the charge transport and photoluminescence quantum yields of the PeNCs. Herein, we investigated the dual functional abilities of bulky cyclic organic ammonium cations as surface-passivating agents and charge scavengers to overcome the lability and insulating nature of conventional long-chain type oleyl amine and oleic acid ligands. Here, red-emitting hybrid PeNCs of the composition CsxFA(1-x)PbBryI(3-y) are chosen as the standard (Std) sample, where cyclohexylammonium (CHA), phenylethylammonium (PEA) and (trifuluoromethyl)benzylamonium (TFB) cations were chosen as the bifunctional surface-passivating ligands. Photoluminescence decay dynamics showed that the chosen cyclic ligands could successfully eliminate the shallow defect-mediated decay process. Further, femtosecond transient absorption spectral (TAS) studies uncovered the rapidly decaying non-radiative pathways; i.e., charge extraction (trapping) by the surface ligands. The charge extraction rates of the bulky cyclic organic ammonium cations were shown to depend on their acid dissociation constant (pKa) values and actinic excitation energies. Excitation wavelength-dependent TAS studies indicate that the exciton trapping rate is slower than the carrier trapping rate of these surface ligands.

Direct Observation of Intragrain Defect Elimination in FAPbI3 Perovskite Solar Cells by Two-Dimensional PEA2PbI4

Two-dimensional perovskites have widely been used to improve the efficiency and stability of perovskite solar cells and are generally believed to passivate defects at the grain boundaries of three-dimensional perovskites. Herein, we studied introducing various combinations of two-dimensional phenyl ethylammonium lead iodide (PEA2PbI4) and methylammonium chloride (MACl) to the formamidinium lead iodide (FAPbI3) precursor solution. Ultralow dose selected area electron diffraction studies prove that the high density of intragrain planar defects in FAPbI3 can be strongly reduced by adding PEA2PbI4 and fully eliminated by adding further MACl. Although PEA+ is too large to incorporate into FAPbI3, PEA2PbI4 not only improves crystallization but also suppresses intragrain defect formation. As a result, a longer charge carrier lifetime, higher photoluminescence quantum yield, lower Urbach energy, and current–voltage hysteresis are achieved, resulting in a champion PCE of 23.69%, with an improvement of humidity stability.

Role of organic cations in tuning the exciton binding energy of 2D lead iodide perovskite derivatives

Control over the exciton binding energy (Eb) in two-dimensional (2D) perovskites can enable their application in a broad range of optoelectronic technologies. To investigate the effects of organic cations on the excitonic properties of 2D perovskites, films of lead iodide hybrids basing on four structurally similar cations of phenylethylammonium (PEA), 4-florophenylethylammonium (FPEA), 4-chlorophenylethylammonium (ClPEA) and 4-bromophenylethylammonium (BrPEA) were prepared and their optical properties were characterized. Results show that both the perovskite layer distortion and exciton absorption/emission peak do not vary too much by the substitution of halogen atom in the para H of phenylethyl cation. Further examination of the temperature-dependent exciton emission properties reveals that the thermal activation energy Ea, which can also be regarded as exciton binding energy in our work, can be tuned over ca. 170 meV within the set of hybrids. It is found that exciton binding energy is sensitive to the identity of organic cations and to the resulting PbI6 octahedron distortion. Among the compounds considered, FPEA based perovskite has the biggest PbI6 octahedron distortion and the largest calculated Ea of 330 meV, while the Br-PEA based perovskite shows a smaller octahedron distortion and the lowest calculated Ea. We believe that an enhanced polarizability of organic cations may be responsible for the observed decrease in octahedra distortion and Ea for the p-halophenylethylammonium lead iodide perovskite derivatives.

Highly Efficient and Stable FA-Based Quasi-2D Ruddlesden-Popper Perovskite Solar Cells by the Incorporation of β-Fluorophenylethanamine Cations.

2D Ruddlesden-Popper (2D RP) perovskite, with attractive environmental and structural stability, has shown great application in perovskite solar cells (PSCs). However, the relatively inferior photovoltaic efficiencies of 2D PSCs limit their further application. To address this issue, β-​fluorophenylethanamine (β-​FPEA) as a novel spacer cation is designed and employed to develop stable and efficient quasi-2D RP PSCs. The strong dipole moment of the β-​FPEA enhancesthe interactions between the cations and [PbI6 ]4- octahedra, thus improving the charge dissociation of quasi-2D RP perovskite. Additionally, the introduction of the β-​FPEA cation optimizesthe energy level alignment, improvesthe crystallinity, stabilizesboth the mixed phase and a-FAPbI3 phase of the quasi-2D RP perovskite film, prolongsthe carrier diffusion length, increasesthe carrier lifetime and decreasesthe trap density. By incorporating the β-​FPEA, the quasi-2D RP PSCs exhibita power conversion efficiency (PCE) of 16.77% (vs phenylethylammonium (PEA)-based quasi-2D RP PSCs of 12.81%) on PEDOT:PSS substrate and achievea champion PCE of 19.11% on the PTAA substrate. It is worth noting that the unencapsulated β-​FPEA-based quasi-2D RP PSCs exhibitconsiderably improved thermal and moisture stability. These findings provide an effective strategy for developing novel spacer cations for high-performance 2D RP PSCs.

Mixed Organic Halide Perovskite Energy Harvester for Solar Cells

Organic- inorganic hybrid perovskite shows promising properties such as optical, electrical, and magnetic. To address issues in the standard methylammonium lead iodide perovskite such as toxicity and stability, lead was replaced with Cu in metal ion part and iodine replaced by chlorine in the anionic position. In this work, methyl ammonium copper chloride (MA2CuCl4) and phenyl ethyl ammonium copper chloride (PEA2CuCl4) were synthesised. Optical and structural property variations of solution obtained by mixing MA2CuCl4 and PEA2CuCl4 in 1:1 ratio was studied. Methylammonium lead iodide has a wide range of applications, particularly in solar cells and photovoltaic systems. Phenylethyl ammonium copper chloride material exhibits both ferroelectric and ferromagnetic properties. Methylammonium copper chloride is hygroscopic and unstable. To increase the stability of the material the organic part can be replaced with higher-order functional groups. Phenylethyl ammonium copper chloride is found to be thermally stable and has more moisture resistance ability compared to methyl ammonium copper chloride. From angle of efficiency, methyl ammonium copper chloride possessed higher performance than phenylethyl ammonium copper chloride, particularly in the field of solar cell perovskites. Uv-vis spectroscopy, FE-SEM, XRD, FTIR characterizations were done.

Photoluminescence Modulation of Ruddlesden-Popper Perovskite via Phase Distribution Regulation.

The intrinsic chaotic phase distribution in Ruddlesden-Popper Perovskite (RPP) hinders its further improvement of photoluminescence (PL) emission and limits its application in optical devices. In this work, we achieve the phase distribution regulation of RPP by varying the composition ratio of organic bulky spacer cations 1-naphthylmethylamine (NMA) and phenylethyl-ammonium (PEA), which is controllable and nondestructive for structures of RPP. By suppressing the small n-phase, the PL intensity emission of RPP is further improved. Through the time-resolved PL (TRPL) measurements, we find the PL lifetime of the sample with 66% PEA concentration increases with the temperature initially and possesses the highest values of τ1 and τ2 at ~255 K, indicating the immediate state assisting exciton radiative recombination, and it can be modulated by phase manipulation in RPP. The immediate state may outcompete other non-radiative decay channels for excited carriers, leading to the PL enhancement in RPP, and broadening its further application.

Spacer cation engineering in Ruddlesden-Popper perovskites for efficient red light-emitting diodes with recommendation 2020 color coordinates

Ruddlesden-Popper perovskites (RPPs) have been demonstrated as a very promising approach for tuning the emission color of perovskite light-emitting diodes (PeLEDs). However, achieving high-performance red PeLEDs with recommendation 2020 color coordinates is still challenging due to the lack of reasonable control over the properties of RPP films. Here, we demonstrate that the judicious selection of spacer cations in RPPs affords a lever for engineering their film properties, including phase distribution, energy funneling process, trap density, and carrier mobility. Four structurally related spacer cations, benzylammonium (BZA), phenylethylammonium (PEA), 3-phenyl-1-propylammonium (PPA), and phenoxyethylammonium (POEA), are studied. Owing to narrow phase distribution, efficient energy funneling, and low trap density, the POEA-based RPP films enable efficient red PeLEDs with a peak external quantum efficiency of 10.3%, a maximum brightness of 1052 cd m−2, and excellent spectral stability. Significantly, the electroluminescence spectrum represents CIE 1931 color coordinates of (0.71, 0.29), which meets the recommendation 2020 standard (0.708, 0.292). The findings provide useful guidelines for the rational design of new organic spacer cations for RPPs with high performance.

Boosting Charge Transport in a 2D/3D Perovskite Heterostructure by Selecting an Ordered 2D Perovskite as the Passivator

AbstractWe demonstrate that an ordered 2D perovskite can significantly boost the photoelectric performance of 2D/3D perovskite heterostructures. Using selective fluorination of phenyl‐ethyl ammonium (PEA) lead iodide to passivate 3D FA0.8Cs0.2PbI3, we find that the 2D/3D perovskite heterostructures passivated by a higher ordered 2D perovskite have lower Urbach energy, yielding a remarkable increase in photoluminescence (PL) intensity, PL lifetime, charge‐carrier mobilities (ϕμ), and carrier diffusion length (LD) for a certain 2D perovskite content. High performance with an ultralong PL lifetime of ≈1.3 μs, high ϕμ of ≈18.56 cm2 V−1 s−1, and long LD of ≈7.85 μm is achieved in the 2D/3D films when passivated by 16.67 % para‐fluoro‐PEA2PbI4. This carrier diffusion length is comparable to that of some perovskite single crystals (>5 μm). These findings provide key missing information on how the organic cations of 2D perovskites influence the performance of 2D/3D perovskite heterostructures.

Boosting Charge Transport in a 2D/3D Perovskite Heterostructure by Selecting an Ordered 2D Perovskite as the Passivator.

We demonstrate that an ordered 2D perovskite can significantly boost the photoelectric performance of 2D/3D perovskite heterostructures. Using selective fluorination of phenyl-ethyl ammonium (PEA) lead iodide to passivate 3D FA0.8 Cs0.2 PbI3 , we find that the 2D/3D perovskite heterostructures passivated by a higher ordered 2D perovskite have lower Urbach energy, yielding a remarkable increase in photoluminescence (PL) intensity, PL lifetime, charge-carrier mobilities (ϕμ), and carrier diffusion length (LD ) for a certain 2D perovskite content. High performance with an ultralong PL lifetime of ≈1.3 μs, high ϕμ of ≈18.56 cm2 V-1 s-1 , and long LD of ≈7.85 μm is achieved in the 2D/3D films when passivated by 16.67 % para-fluoro-PEA2 PbI4 . This carrier diffusion length is comparable to that of some perovskite single crystals (>5 μm). These findings provide key missing information on how the organic cations of 2D perovskites influence the performance of 2D/3D perovskite heterostructures.

High-frequency pulsed-electroluminescence from light-emitting diodes based on quasi-2D perovskites (rubidium-doped CsPbBr3)

We report high-frequency pulsed-electroluminescence generation from light-emitting diodes (LEDs) based on quasi-2D perovskites under AC voltages. The quasi-2D form of CsPbBr3 was obtained upon the inclusion of a larger-sized organic cation, namely phenylethylammonium (PEA); the defects in the perovskite were passivated through rubidium-incorporation. The conversion of the perovskite to a lower-dimensional form, along with defect-passivation, has led to the enhancement of PL emission and thereby yielded increased electroluminescence (EL) intensity from the LEDs based on the perovskites. While the devices under a DC voltage have emitted EL only under a forward-bias section, the LEDs operated with AC voltages have resulted in pulsed-light and EL-emissions under reverse-biased half-cycles as well. In this work, we have recorded the dynamic response of the pulsed-light generated from LEDs under AC voltages and varied its frequency to correlate the effect of defect-passivation (through rubidium-doping) with the frequency–response of pulsed EL-emission.

Elucidating the role of two-dimensional cations in green perovskite light emitting diodes

Perovskite light emitting diodes (PeLEDs) have emerged as promising candidates for applications requiring visible and near-infrared emission. Lead-based quasi-2D perovskite materials are commonly employed as an emissive layer for PeLEDs as they promote radiative emission via spatially confining excitons and funnelling of charge carriers. Designing efficient emissive layers based on these quasi-2D perovskites requires that the ratio between inorganic [PbX 6 ] 4- component and the large organic cations (spacers) is carefully optimized. In this work, we demonstrate the importance of such compositional tuning using three different 2D cations namely phenylethylammonium (PEA), its monofluorinated analogue FPEA and a custom-made bulkier cation BPEA containing an extra phenyl ring. Our results show that the tuning of the ratio between 2D cation and the [PbX 6 ] 4- provides a trade-off between electrical transport in the device and the emission properties of the emissive layer. Generally, a large excess of cations is required to enhance the external quantum efficiency (EQE) of PeLEDs. Among the various cations, FPEA leads to PeLEDs with the highest EQE up to 7.7%, while BPEA resulted in the smallest EQE. Atomic force microscopy, space-charge-limited current, steady-state and time-resolved photoluminescence results revealed that FPEA-based perovskite have lower number of pinholes and traps compared to PEA, while it is also likely to have better charge transport properties due to its smaller size in contrast to BPEA. Our results provide guidelines regarding the multiple functions an organic spacer needs to fulfil for fabricating efficient PeLEDs. • Three quasi-2D cations are employed in perovskite emissive layer. • A change in the molar ratio of cation impact optoelectronic properties. • A trade-off between electrical transport and emission properties is found. • Peak EQE of 7.7% is obtained for optical FPEABr cation. • The 2D cations improved stability of green PeLEDs.