Dion-Jacobson Phase Research Articles

Highly stable and self-powered ultraviolet photodetector based on Dion-Jacobson phase lead-free double perovskite

Metal halide perovskite materials present a wide array of opportunities for the development of high-performance optoelectronic devices, owing to their outstanding photoelectric properties. Compared with the lead-containing perovskites, stable and non-toxic organic-inorganic hybrid perovskites exhibit enhanced potential for future commercial applications. In this work, we developed a self-powered UV photodetector based on 2D Dion−Jacobson (DJ) phase lead-free double perovskite HAAg0.5Bi0.5Br4 (HA2+ = histammonium) perovskite with an on-off ratio up to 2.66 × 106, excellent specific detectivity of 6 × 1012 Jones, and response speed of 1.32 ms/118.4 μs. The light intensity related pyro-phototronic effect on 2D perovskite is thoroughly investigated. Temperature and light detection are realized through multi-energy coupling, which greatly improves the detection performance. Coupled pyro-phototronic current is calculated nearly 75 folds higher than that from the photoelectronic merely. As-prepared photodetector film shows excellent stability in normal environment, maintaining a value of 90 % to the initial performance after 500 cycles and 90 days. This work provides a new self-powered, stable and non-toxic candidate for the future UV photodetectors.

Ultralow thermal conductivity of 2D Dion-Jacobson (PDA)(FA)n - 1PbnI3n + 1 perovskite films.

Two-dimensional (2D) perovskites exhibit enhanced thermal stability compared to three-dimensional perovskites, especially the emerging 2D Dion-Jacobson (DJ) phase perovskite. However, the heat transfer mechanisms in DJ phase perovskites are rarely reported. Herein, we determine thermal conductivities of (PDA)(FA)n - 1PbnI3n + 1 films with n = 1-6 by time-domain thermoreflectance. The measured results indicate that the thermal conductivities of these films are extremely low, showing a trend from decline to rise with increasing n values, and reaching to the lowest when n = 2. We measure the propagation of acoustic phonons in films with n = 1-3 by time-domain Brillouin scattering and find phonon velocity plays a key role in the thermal conductivity, which can be explained by the mismatch of spring constants between the inorganic layer and the organic layer using the bead-spring model. The gradually increasing thermal conductivity for larger n values is attributed to the gradual transformation of the grain orientation from horizontal to vertical, which is demonstrated by the grazing-incidence wide-angle x ray scattering (GIWAXS) results. Our work deepens the understanding of the thermal transport process in 2D DJ phase perovskite films and provides insights into thermal management solutions for their devices.

Data-Driven Design of Electroactive Spacer Molecules to Tune Charge Carrier Dynamics in Layered Halide Perovskite Heterostructures.

Crafting rational heterojunctions with nanostructured materials is instrumental in fostering effective interfacial charge separation and transport for optoelectronics. Layered halide perovskites (LHPs) that form heterojunctions between organic spacer molecules and inorganic metal halide layers exhibit tunable photophysics owing to their customizable band alignment. However, controlling photogenerated carrier dynamics by strategically designing layered perovskite heterojunctions remains largely unexplored. We combine a data-driven approach with time-domain density functional theory (TD-DFT) and non-adiabatic molecular dynamics (NAMD) to screen and select electronically active spacer dications (A') that introduce a type-II heterojunction in the lead iodide-based Dion-Jacobson phase LHPs. The composition-structure-electronic property correlations reveal that the number of nitrogens in aromatic heterocycles is the key factor in designing electron-accepting spacers in these perovskites. The detailed atomistic simulations validate the design strategy further by modeling (A')PbI4 perovskites, which incorporate three different screened electroactive A' spacers. The computed excited charge carrier dynamics illustrate the phonon-mediated ultrafast interfacial electron transfer from the inorganic conduction band edge to the lower-lying unoccupied orbitals of spacers, exhibiting photoluminescence quenching in these (A')PbI4 perovskites. The spatially separated electrons and holes at the type-II heterojunction interface prolong the excited charge carrier lifetime, boosting the carrier transport and exciton dynamics. Our work illustrates a robust in silico approach for designing LHPs with exciting optoelectronic properties originating from their fine-tuned heterojunctions.

Promoting energy transfer via manipulation of crystallization kinetics of quasi-2D Dion–Jacobson phase perovskites for high-performance green lasers

The quasi-2D Dion–Jacobson perovskite exhibits significant photophysical properties and potential applications. However, the insufficient exciton energy transfer leads to nonradiative recombination that seriously hinders charge transport. Here, an efficient energy transfer is achieved by incorporating the alkali metal, which not only constrains the nucleation of high-n phases and promotes the growth of the middle-n phases but also optimizes the phase distribution and the crystal orientation to promote carrier transport. We achieve a green amplified spontaneous emission with a low threshold of 28.5 μJ/cm2 and a vertical-cavity laser operating in a single-mode configuration with a linewidth of 0.96 nm.

Tin doping modulates electron-hole recombination in Dion-Jacobson phase 2D hybrid perovskite

To obtain less-toxic and optimal-band-gap perovskite materials, tin (Sn)-lead (Pb) hybrid technology comes into the sight of researchers. The Sn–Pb ratio primarily affects the electronic band structure, conductivity, and carrier transport, which are essential for optoelectronic performance. While most reports are about 3D materials, there has been little coverage of 2D Sn–Pb perovskites which exhibiting improved stability. In this paper, the e-h recombination dynamics in Dion-Jacobson Phase 2D Sn–Pb perovskites are studied using time-dependent ab initio nonadiabatic molecular dynamics (NAMD) simulation. It is found that Sn doping plays a significant role in narrowing the band-gap of 2D perovskites and localizing the charge distribution. Only a small amount of Sn doping can minimize NA coupling and shorten decoherence time of frontier orbitals simultaneously, then leading to longer charge recombination time. NAMD simulations reveal the optimal Sn ratio (25 mol%) and provide an effective way to design high-performance 2D perovskite materials.

Enhanced performance of amplified spontaneous emission in Dion-Jacobson phase quasi-2D perovskite by facilitating carrier co-radiation.

Dion-Jacobson (DJ) structured quasi-2D perovskites are promising candidates for new generation gain medium due to their excellent photoelectric performance, super environmental, and structure stability. The isolated carrier recombination with inhomogeneous mixed phase is detrimental in enhancing amplified spontaneous emission (ASE) of optically pumped DJ phase quasi-2D perovskites lasers. Here, in 1.3-propanediamine (PDA)-based DJ perovskites, the carrier dynamic behavior from the pristine sample to the Cremophor EL (Cre EL) treated sample is unraveled. Remarkably, the Cre EL treated sample displays a well-proportioned large n domain distribution, resulting in an increased radiation-state density and hence enhancing collaboration emitting between carriers. The improved collaboration emitting promotes carriers' fast relay radiation, resulting in a higher ASE performance with a threshold reduced from 11.7 to 4.8μJ/cm2, optical gain coefficient increased from 775 to 1559 cm-1 and degree-of-polarization (DOP) improved from 0.59 to 0.98. Our findings suggest that the development of DJ structured quasi-2D perovskite laser gain medium should target facilitating fast carrier co-radiation recombination.

Controlled dion-jacobson low-dimensional surface phase enables highly efficient and stable perovskite solar cells

The 2D/3D heterojunction structure emerges as a viable approach for enhancing the efficiency and stability of perovskite photovoltaics. However, the formation of an accumulative low-dimensional 2D perovskite (n=1) cladding layer often impedes carrier transport due to the insulating nature and high quantum confinement, and there is a paucity of detailed understanding regarding its surface phase control. This study introduces a Dion-Jacobson (DJ) phase 2D perovskite, employing decane-1,10-diammonium diiodide (DDADI) to interface with 3D perovskite, leveraging long-chain diammonium cations for structural stability and defect passivation on the 3D FAPbI3 perovskite surface. In addition, a novel PbI2-assisted phase control (PAPC) technique is proposed to mitigate the quantum confinement effects of the 2D layer, especially reducing the formation of the highly confined insulating n=1 phase. X-ray scattering analysis confirms the method's efficacy in promoting the formation of an n=2 phase, facilitating cascading HOMO levels and improving hole carrier transport. The optimized 2D/3D perovskite solar cell (PSC) achieve an exemplary efficiency of 25.16 %, with a notable open-circuit voltage of 1.192 V, and retain 92.9 % of its initial efficiency after 1000 hours in a nitrogen atmosphere, signifying a strategic advancement in 2D/3D PSC construction.

Gradient Dion‐Jacobson Phase Stable Quasi‐2D Perovskite@Graphene Hybrid for High Responsivity Photodetectors

AbstractQuasi‐(2D) formamidinium lead‐iodide (FAPbI3) perovskites are winsome materials for high‐performance photodetectors (PDs). Between Ruddlesden‐Popper (RP) and Dion‐Jacobson (DJ) phases, the latter exhibits lower non‐radiative recombination and higher mobility compared to the relatively easily synthesized former. For efficient charge separation and transport, graphene‐assisted two‐terminal coplanar PD leveraging the DJ phase perovskite is proposed. Diamino octane (DAO), incorporated into 3D FAPbI3 perovskite, resulted in DJ phase [DAO(FA)n‐1PbnI3n+1], n being predefined integers 1≤ n ≤ ∞, demonstrating a vertical gradient heterostructure of n phases. Superior crystallinity and thermal stability of the quasi‐2D films are confirmed via synchrotron‐based studies. Band‐edge of the 3D film blue‐shifted consistently from 810 nm, while passing through the quasi‐2D phases, to ≈500 nm for the 2D phase. The dynamic range of photoresponsivity (R) of PDs reflected the absorption trend, with the 2D perovskite being infrared blind. Graphene's high carrier mobility coupled with the perovskite's high absorbance resulted in an unprecedented high R of ≈107 A W−1 and specific detectivity of 9.77 × 1016 Jones under 42.25 nW cm−2 of 405 nm illumination for the predefined n = 2 film. This underscores the potential of the DJ phase quasi‐2D perovskite@graphene in realizing stable, sensitive, and spectrally tunable PDs.

Piperidine and Pyridine Series Lead-Free Dion-Jacobson Phase Tin Perovskite Single Crystals and Their Applications for Field-Effect Transistors.

Two-dimensional (2D) organic-inorganic metal halide perovskites have gained immense attention as alternatives to three-dimensional (3D) perovskites in recent years. The hydrophobic spacers in the layered structure of 2D perovskites make them more moisture-resistant than 3D perovskites. Moreover, they exhibit unique anisotropic electrical transport properties due to a structural confinement effect. In this study, four lead-free Dion-Jacobson (DJ) Sn-based phase perovskite single crystals, 3AMPSnI4, 4AMPSnI4, 3AMPYSnI4, and 4AMPYSnI4 [AMP = (aminomethyl)-piperidinium, AMPY = (aminomethyl)pyridinium] are reported. Results reveal structural differences between them impacting the resulting optical properties. Namely, higher octahedron distortion results in a higher absorption edge. Density functional theory (DFT) is also performed to determine the trends in energy band diagrams, exciton binding energies, and formation energies due to structural differences among the four single crystals. Finally, a field-effect transistor (FET) based on 4AMPSnI4 is demonstrated with a respectable hole mobility of 0.57 cm2 V-1 s-1 requiring a low threshold voltage of only -2.5 V at a drain voltage of -40 V. To the best of our knowledge, this is the third DJ-phase perovskite FET reported to date.

Highly efficient and stable Dion–Jacobson(DJ) 2D-3D perovskite solar cells with 26 % conversion efficiency: A SCAPS-1D study

This paper includes the theoretical investigation performed on the device having structure FTO/TiO2/CH3NH3PbI3/PeDAMAPb4I16/Spiro- OMeTAD. This work is focused on the effects of ETLs and HTLs on the performance of the device structure. Device simulation and various parameters of the perovskite cell are investigated with the help of SCAPS-1D software. In recent years, perovskite solar cells (PSCs) have passed through many advancements but they suffered through instability due to moisture. Due to poor stability of PSCs becomes a major obstacle for its commercialization. This leads to the development of 2D perovskite manufactured from organic cations and inorganic slabs arranged alternately.2D perovskite is of two kinds: Ruddlesden - Popper (RP) phase and Dion-Jacobson (DJ) phase. Both types of 2D perovskite are observed to be much more stable than 3Dperovskite. Due to its stability, it becomes an alternative for 3D perovskite. To improve the stability and efficiency of 2D perovskite both types of 2D phases are merged. To have more stability organic cations are introduced between inorganic slabs which reduces charge transportation. Proposed DJ 2D-3D perovskite solar cells provide an impressive efficiency of 26.03 % even when exposed to much temperature and moisture. Being much more efficient and stable the 2D-DJ/3D perovskite becomes an option to be utilized in photovoltaic applications.

Two-Dimensional Double Perovskites in the Dion–Jacobson Phase Alleviate Parity Forbidden Transitions for Photovoltaic Applications

Two-Dimensional Double Perovskites in the Dion–Jacobson Phase Alleviate Parity Forbidden Transitions for Photovoltaic Applications

Correlating π-π Stacking of Aromatic Diammoniums with Stability and Dimensional Reduction of Dion-Jacobson 2D Perovskites.

Dion-Jacobson (DJ) phase 2D perovskites with various aromatic diammonium cations, potentially possessing high stability, have been developed for optoelectronics. However, their stability does not meet initial expectations, and some of them even easily degrade into lower-dimensional structures. Underlying the stability mechanism and dimensional reduction of these DJ 2D perovskites remains elusive. Herein, we report that π-π stacking intensity between aromatic cations determines structural stability and dimensional variation of DJ 2D perovskites by investigating nine benzene diammoniums (BDAs)-derived low-dimensional perovskites. The BDAs without intermolecular π-π stacking form stable DJ 2D perovskites, while those showing strong π-π stacking tend to generate 1D and 0D architectures. Furthermore, the π-π stacking intensity highly relies on molecular symmetry and electrostatic potential of BDAs; namely, asymmetry and small dipole moment facilitate alleviating the π-π stacking, leading to the formation of DJ 2D perovskites and vice versa. Our findings establish the relationship of aromatic diammonium structure-π-π stacking interaction-perovskite dimensionality, which can guide the design of stable DJ 2D perovskites and the manipulation of perovskite dimensionality for various optoelectronic applications.

Improved contact of “Spiro-OMeTAD/perovskite” interface by hydrophilic 1, 6-hexanediammonium diiodide molecule and the accelerated charge extraction processes

Hydrophilic 1, 6-hexanediammonium diiodide (HDADI) is used to modify the perovskite surface, so as to improve the contact between the “Spiro-OMeTAD/perovskite” interface. It is observed that, after moderate HDADI modification, the wettability of Spiro-OMeTAD/chlorobenzene solution on perovskite is improved. After modified at moderate concentration of HDADI, surface roughness of perovskite film decreases from 19.4 to 15.8 nm, while that of Spiro-OMeTAD (coated on perovskite) decreases from 7.54 to 6.53 nm, indicating better interfacial contact. The improved interfacial contact is due to the hydrophilic nature of the HDADI molecule, and the formed two-dimensional (2D) Dion–Jacobson phase perovskite, as revealed by x-ray diffraction and x-ray photoelectron spectroscopy studies. Photoluminescence and Mott–Schottky studies show that defects are reduced. Accordingly, the charge-extraction rate is accelerated, while recombination is reduced according to transient photovoltaic/photocurrent decay curves tests and impedance spectroscopy. Photo-to-electric power conversion test demonstrates that the modification helps upgrade the power conversion efficiency of perovskite solar cells from 20.25 (±0.85)% to 22.28 (±0.53)% (with a champion efficiency of 23.08%). In addition, device stability has also been prolonged. This study provides an efficient strategy to strengthen the contact between the “Spiro-OMeTAD/perovskite” interface.

Self-trapped emissions in 2D lead-free halide perovskites driven by divalent spacer cations.

The mono- and divalent spacer cation investigation in sodium/indium-based 2D double perovskites revealed significant impacts on optoelectronic properties due to distortions in the inorganic layers. The strong electron-phonon coupling in a novel lead-free Dion-Jacobson phase highlights a promising class for broad-emission devices based on self-trapped excitons (STE), offering enhanced structural stability.

Energy Transfer and Self-Trapping Exciton Luminescence in Sb3+-Doped Two-Dimensional Layered Dion–Jacobson Phase Cadmium-Based Perovskites

Energy Transfer and Self-Trapping Exciton Luminescence in Sb³⁺-Doped Two-Dimensional Layered Dion–Jacobson Phase Cadmium-Based Perovskites

Dion–Jacobson Phase Perovskite Crystal Assembled by π‐Conjugated Aromatic Spacer for X‐Ray Detectors with an Ultralow Detection Limit

Abstract2D Dion–Jacobson (DJ) perovskites recently have attracted extensive attention for X‐ray detection owing to their structural rigidity and environmental stability. The chemical incorporation of π‐conjugation aromatic spacing cations into DJ phase perovskites will increase the rigidity of cation and electron cloud density between adjacent inorganic slabs, thus facilitating structural rigidity and charge transport. However, it is still a challenge to synthesize high‐quality single crystals of DJ phase perovskite with aromatic spacers for detecting X‐ray applications. Here, a new DJ phase perovskite by introducing π‐conjugated aromatic cation spacer, (4ABA)PbI4 (1, 4ABA = 4‐aminobenzylamine), eliminating the van der Waals gap is designed. High‐quality single crystals of 1 are grown via the facile solution method, exhibiting high resistivity (1.97 × 1011 Ω cm), low trap density (3.36 × 109 cm−3), and large carrier mobility‐lifetime product (1.03 × 10−3 cm2 V−1) under X‐ray illumination. Such remarkable physical characteristics endow single crystal 1 detector with high‐performance X‐ray detection including a high sensitivity of 572 µC Gyair−1cm−2, an ultralow detection limit of 7.50 nGyair s−1 and exceptional radiation stability. The X‐ray detection limit of 1 is over 700 times lower than that of routine medical diagnosis (5500 nGyair s−1), demonstrating potential applications in medical examination.

Quasi-2D Dion-Jacobson phase perovskites as a promising material platform for stable and high-performance lasers.

Metal halide perovskites have shown outstanding optoelectronic and nonlinear optical properties; yet, to realize wafer-scale high-performance perovskite-integrated photonics, the materials also need to have excellent ambient stability and compatibility with nanofabrication processes. In this work, we introduce Dion-Jacobson (D-J) phase perovskites for photonic device applications. By combining self-assembled monolayer-assisted film growth with thermal pressing, we obtain a series of compact and extremely smooth D-J phase perovskite thin films that exhibit excellent stability during electron-beam lithography, solvent development, and rinse. Combining spectroscopic and morphological characterizations, we further demonstrate how organic spacers can be used to fine-tune the photophysical properties and processability of the perovskite films. The distributed-feedback lasers based on the D-J phase perovskites exhibit a low lasing threshold (5.5 μJ cm-2 pumped with nanosecond laser), record high Q factor (up to 30,000), and excellent stability, with an unencapsulated device demonstrating a T90 beyond 60 hours in ambient conditions (50% relative humidity).

Exploring A‐Site Cation Variations in Dion–Jacobson Two‐Dimensional Halide Perovskites for Enhanced Solar Cell Applications: A Density Functional Theory Study

The exceptional photophysical and electronic properties of 2D hybrid perovskites possess potential applications in the field of solar energy harvesting. The present work focuses on the two systems, exhibiting the Dion–Jacobson phase of 2D perovskite consisting of methylammonium (MA) and formamidinium (FA) cations at A‐site and 3‐(aminomethyl)pyridinium (3AMPY) as ring‐shaped organic spacer. Altering A‐site cations creates a distortion of inorganic layers and hydrogen bond interactions. It has been noted that the angles of Pb–I–Pb and I–Pb–I are more symmetric (close to 180°) for (3AMPY)(MA)Pb2I7 compared to (3AMPY)(FA)Pb2I7 and result in increase of bandgap from 1.51 to 1.58 eV. This further leads to a significant difference in Rashba splitting energy under the influence of spin‐orbit coupling effects, where the highest splitting (36 meV) is calculated for conduction band edge of the (3AMPY)(FA)Pb2I7, suggesting the promising applications toward spintronics. The calculated absorption spectra cover the range from 300 to 450 nm, indicating significant optical activity of 2D (3AMPY)(MA)Pb2I7 and (3AMPY)(FA)Pb2I7 in the visible and ultraviolet regions, which bodes well for their application in advanced optoelectronic devices. The bandgap and high absorption coefficients present more than 30% of theoretical power conversion efficiency for both systems, as calculated from the spectroscopic‐limited maximum efficiency.

Ambient-Stable 2D Dion-Jacobson Phase Tin Halide Perovskite Field-Effect Transistors with Mobility Over 1.6 Cm2 V-1 S-1.

Solution-processed metal halide perovskites hold immense potential for the advancement of next-generation field-effect transistors (FETs). However, the instability of perovskite-based transistors has impeded their progress and practical applications. Here we report ambient-stable high-performance FETs based on two-dimensional Dion-Jacobson phase tin halide perovskite BDASnI4 that has high film quality and excellent electrical properties. The perovskite channels are established by engineering the film crystallization process via the employment of ammonium salt interlayers and the incorporation of NH4 SCN additives within the precursor solution. The refined FETs demonstrate field-effect hole mobilities up to 1.61 cm2 V- 1 s- 1 and an on/off ratio surpassing 106 . Moreover, the devices show impressive operational and environmental stability, and retain their functional performance even after being exposed to ambient conditions with temperature of 45°C and humidity of 45% for over 150 hours. This article is protected by copyright. All rights reserved.

Modulation Phase Distribution of Ruddlesden-Popper Quasi-2D Perovskites with a Similarly Spaced Dion-Jacobson Phase.

Quasi-two-dimensional (quasi-2D) perovskites exhibit excellent performance when applied to light-emitting diodes (LEDs). However, quasi-2D perovskite films generally have nonuniform n phases and irregular internal crystal structures, which degrade the device's performance. Here, we propose using a Dion-Jacobson (DJ)-type organic spacer to modulate the phase distribution of the Ruddlesden-Popper (RP) quasi-2D perovskite. A DJ-type organic spacer cation, 1.6-hexamethylenediamine (HDABr2), was introduced into the perovskite as the second spacer cation with propylamine hydrobromide (PABr). As DJ-type and RP-type perovskites have similar spacings, RP-DJ style does not cause a chaotic crystalline structure; instead, it modulates the perovskite crystallization and narrows the phase distribution. In parallel, there is a substantial improvement in the maximum luminance, current efficiency, external quantum efficiency, and device stability of the quasi-2D perovskite LEDs. This work provides a novel concept for combining the organic spacer cations for quasi-2D perovskites.