Hybrid Organic-inorganic Lead Halide Perovskites Research Articles

Solution Processed Hybrid Lead Perovskite Films for White Light Emission and Lasing Applications

Abstract2D organic–inorganic hybrid lead halide perovskite films are fascinating optoelectronic materials for white‐light emission and lasing applications. Here, it is demonstrated that nano‐meter‐thick films of perovskites can be formed at room temperature using Langmuir–Schaefer (LS) deposition technique. In situ X‐ray measurements reveal a self‐assembly process of the 2D perovskite formation at the air–water interface. This formation process requires the presence of stearic acid monolayer on the water subphase having a solution of lead‐perovskite in dimethylformamide. Microscopy and X‐ray measurements of these nanofilms transferred onto substrates show crystalline phase formation that deviates from the known orthorhombic structure of the bulk crystals. The nanofilms exhibit novel broad optical emission with sharp band‐edge transition in temperature‐dependent photoluminescence studies. Also, their band‐edge emission is distinctly blue‐shifted compared to that of thicker 2D perovskite flakes prepared by the slow‐cooling chemical synthesis process. 2D flakes exhibit lasing that cannot be obtained in the LS nanofilms as their thicknesses are lower than the lasing wavelength prohibiting wave‐guide formation. The results show that the 2D single‐crystalline nature of the LS films and flakes are suitable materials to develop broad‐band white light emission across the entire visible range and to obtain lasing without external cavities, respectively.

Coherent Carrier Spin Dynamics in FAPbBr3 Perovskite Crystals.

Coherent spin dynamics of electrons and holes are studied in hybrid organic-inorganic lead halide perovskite FAPbBr3 bulk single crystals using the time-resolved Kerr ellipticity technique at cryogenic temperatures. The Larmor spin precession of the carrier spins in a magnetic field is monitored to measure the Landé g-factors of electrons (+2.44) and holes (+0.41). These g-factors are highly isotropic. The measured spin dephasing times amount to a few nanoseconds, and the longitudinal hole spin relaxation time is 470 ns. The important role of the strong hyperfine interaction between carrier spins and nuclear spins is demonstrated via dynamic nuclear polarization. At low temperatures, electron and hole spin relaxation predominantly occurs via the hyperfine interaction, whose importance significantly decreases at temperatures above 12 K. We overview the spin dynamics in various lead halide perovskite crystals and polycrystalline films and conclude on their common features provided by charge carrier localization at cryogenic temperatures.

Compositional Engineering of Hybrid Organic-Inorganic Lead-Halide Perovskite and PVDF-Graphene for High-Performance Triboelectric Nanogenerators.

Triboelectric nanogenerators (TENGs) have attracted a great deal of attention since they can convert ubiquitous mechanical energy into electrical energy and serve as a continuous power source for self-powered sensors. Optimization of the dielectric material composition is an effective way to improve the triboelectric output performance of TENGs. Herein, the hybrid organic-inorganic lead-iodide perovskite Cs0.05FA0.95-xMAxPbI3 was prepared by blade coating and used as a positive friction layer material. Moreover, PVDF-graphene (PG) nanofibers were prepared as negative friction layer materials by electrostatic spinning. The output performance of the TENG was enhanced by varying the MA content of the pervoskite films and the graphene content of the PG nanofibers. The champion output TENG based on Cs0.05FA0.9MA0.05PbI3/PG-0.15 achieved an open-circuit voltage of 245 V, a short-circuit current of 24 μA, and a charge transfer of 80.2 nC. Meanwhile, a maximum power density of 11.23 W m-2 was obtained at 100 MΩ. Moreover, the device exhibits excellent energy-harvesting properties, including excellent stability and durability, rapidly charges capacitors, and lights commercial LEDs and digital tubes.

Phase Transitions, Dielectric Response, and Nonlinear Optical Properties of Aziridinium Lead Halide Perovskites.

Hybrid organic-inorganic lead halide perovskites are promising candidates for next-generation solar cells, light-emitting diodes, photodetectors, and lasers. The structural, dynamic, and phase-transition properties play a key role in the performance of these materials. In this work, we use a multitechnique experimental (thermal, X-ray diffraction, Raman scattering, dielectric, nonlinear optical) and theoretical (machine-learning force field) approach to map the phase diagrams and obtain information on molecular dynamics and mechanism of the structural phase transitions in novel 3D AZRPbX3 perovskites (AZR = aziridinium; X = Cl, Br, I). Our work reveals that all perovskites undergo order-disorder phase transitions at low temperatures, which significantly affect the structural, dielectric, phonon, and nonlinear optical properties of these compounds. The desirable cubic phases of AZRPbX3 remain stable at lower temperatures (132, 145, and 162 K for I, Br, and Cl) compared to the methylammonium and formamidinium analogues. Similar to other 3D-connected hybrid perovskites, the dielectric response reveals a rather high dielectric permittivity, an important feature for defect tolerance. We further show that AZRPbBr3 and AZRPbI3 exhibit strong nonlinear optical absorption. The high two-photon brightness of AZRPbI3 emission stands out among lead perovskites emitting in the near-infrared region.

Optical and structural characterization of CsPb(I1-xBrx)3 nanomaterials prepared by the mechanochemical method

Hybrid organic-inorganic lead halide perovskites (LHP) are gaining considerable attention due to their wide range of potential applications, particularly as an active layer in solar cells and light-emitting devices owing to their excellent light-harvesting and photoluminescence emission properties. Considering their high color purity and color-tunability, high photoluminescence quantum yield (PLQY), easy fabrication, and cost-efficiency, LHP are promising candidates to compete with the traditional active layer in solid-state lighting. The PL emission of CsPbX3 (X = I, Br, Cl) covers the entire visible range from 400 to 730 nm and can be easily tuned via halide replacement in the I ↔ Br ↔ Cl series. In this work, photoluminescence (PL), luminescence excitation, UV/VIS/NIR absorption, structural and morphological properties of CsPb(I1-xBrx)3 (x = 0–1) nanosized powders prepared by the mechanochemical synthesis method is investigated at 80K and room temperature. A narrow PL peak with full width at half maximum (FWHM) = 16.5 and 6.6 nm was observed at room temperature and 80K from CsPbBr3, respectively. The relation between structure and optical properties of nanopowders is discussed. It is shown that the halide exchange mechanism is an effective approach for fabrication of defect-free materials.

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.

Introducing Ferroelasticity into 1D Hybrid Lead Halide Semiconductor by Halogen Substitution Strategy.

Organic-inorganic hybrid lead halide perovskites (OLHPs), represented by (CH3 NH3 )PbI3 , are one of the research focus due to their exceptional performance in optoelectronic applications, and ferroelastic domain walls are benign to their charge carrier transport that is confirmed recently. Among them, the 1DOLHPs feature better stability against desorption and moisture, but related 1D ones possessing ferroelasticity are rarely investigated and reported so far. In this work, the 1D ferroelastic semiconductor (N-iodomethyl-N-methyl-morpholinium)PbI3 ((IDMML)PbI3 ) is prepared successfully by introducing successively halogenate atoms from Cl, Br to I into the organic cation of the prototype (N,N-dimethylmorpholinium)PbI3 ((DMML)PbI3 ). Notably, (IDMML)PbI3 shows the narrow bandgap energy (≈2.34eV) according to the ultraviolet-visible absorption spectrum and the theoretical calculation, and possesses the evident photoconductive characteristic with the on/off ratio of current of ≈50 under the 405nm light irradiation. This work provides a new case for the ferroelastic OLHPs and will inspire intriguing research in the field of optoelectronic.

Long-Lived Exciton Coherence in Mixed-Halide Perovskite Crystals.

Compositional engineering of the optical properties of hybrid organic-inorganic lead halide perovskites is crucial for the realization of efficient solar cells and light-emitting devices. We study the effect of band gap fluctuations on coherent exciton dynamics in a mixed FA0.9Cs0.1PbI2.8Br0.2 perovskite crystal by using photon echo spectroscopy. We reveal a narrow homogeneous exciton line width of 16 μeV at a temperature of 1.5 K. The corresponding exciton coherence time T2 = 83 ps is exceptionally long due to the localization of excitons at the scale of tens to hundreds of nanometers. From spectral and temperature dependences of the two- and three-pulse photon echo decay, we conclude that for low-energy excitons pure decoherence associated with elastic scattering on phonons is comparable with the exciton lifetime, while for excitons with higher energies, inelastic scattering to lower energy states via phonon emission dominates.

A Data-Driven Platform for Two-Dimensional Hybrid Lead-Halide Perovskites.

The exceptional properties of two-dimensional hybrid organic-inorganic lead-halide perovskites (2D HOIPs) have led to a rapid increase in the number of low-dimensional materials for optoelectronic engineering and solar energy conversion. The flexibility and controllability of 2D HOIPs create a vast structural space, which presents an urgent issue to effectively explore 2D HOIPs with better performance for practical applications. However, the traditional RP-DJ classification method falls short in describing the influence of structure on the electronic properties of 2D HOIPs. To overcome this limitation, we employed inorganic structure factors (SF) as a classification descriptor, which considers the influence of inorganic layer distortion of 2D HOIPs. And we investigated the relationship between SF, other physicochemical features, and band gaps of 2D HOIPs. By using this structural descriptor as a feature for a machine learning model, a database of 304920 2D HOIPs and their structural and electronic properties was generated. A large number of previously neglected 2D HOIPs were discovered. With the establishment of this database, experimental data and machine learning methods were combined to develop a 2D HOIPs exploration platform. This platform integrates searching, download, analysis, and online prediction, providing a useful tool for the further discovery of 2D HOIPs.

Minimal Molecular Building Blocks for Screening in Quasi-Two-Dimensional Organic-Inorganic Lead Halide Perovskites.

Layered hybrid organic-inorganic lead halide perovskites have intriguing optoelectronic properties, but some of the most interesting perovskite systems, such as defective, disordered, or mixed perovskites, require multiple unit cells to describe and are not accessible within state-of-the-art ab initio theoretical approaches for computing excited states. The principal bottleneck is the calculation of the dielectric matrix, which scales formally as O(N4). We develop here a fully ab initio approximation for the dielectric matrix, known as IPSA-2C, in which we separate the polarizability of the organic/inorganic layers into minimal building blocks, thus circumventing the undesirable power-law scaling. The IPSA-2C method reproduces the quasi-particle band structures and absorption spectra for a series of Ruddlesden-Popper perovskites to high accuracy, by including critical nonlocal effects neglected in simpler models, and sheds light on the complicated interplay of screening between the organic and inorganic sublattices.

High-performance photodetector based on semi-encompassed CH3NH3PbCl3–ZnO microwire heterojunction with alterable spectral response

Recently, heterojunctions consisting of hybrid organic-inorganic lead (Pb) halide perovskites and other semiconductors have drawn increasing attention for the potential application in photodetectors due to their exceptional performance. However, their performance is usually limited by the relatively low crystalline quality of perovskites, and the response spectra of the devices are difficult to adjust according to the practical requirement. Here, high quality CH3NH3PbCl3 micro-sized crystals have been successfully fabricated on one side of individual ZnO microwire to form heterojunction photodetector by a two-step crystallization method. The heterojunction device presents a low dark current (60 nA at −6 V) along with a rapid response speed (rise time of <20 μs and fall time of ∼500 μs). More interestingly, the modulation of the response spectra and the responsivity can be realized by operating the device under front or back illumination due to the self-filtering properties. Our findings provide a promising method for combining perovskites with other inorganic materials to form high-performance heterojunction photodetectors.

Investigation of thickness dependent efficiency of CsPbX3 (X = I, Br) absorber layer for perovskite solar cells

The drawbacks of solar cells consisting of hybrid organic-inorganic lead halide perovskites led to the development of solar cells containing completely inorganic perovskites. Therefore, here we have carried out detailed density functional theory (DFT) based investigation of cubic phase CsPbX3 (X = I, Br). Absence of imaginary frequencies in phonon dispersion curves and negative cohesive energies of the perovskites depicts stability of our crystal structures. From electronic properties of CsPbI3 and CsPbBr3 we have deduced that the major contributions in their valence band region is due to I-5p and Br-4p orbitals, respectively. The static dielectric constant of CsPbI3 is greater than CsPbBr3 which shows that it consists of low carrier recombination rate. Red shift has also been observed in absorption coefficient plot while going from Br → I in CsPbX3. The thickness of absorber layer present in perovskite solar cells (PSCs) directly influences its efficiency and stability. Therefore, here we have used a detailed framework i.e., spectroscopic limited maximum efficiency (SLME) to predict solar cell parameters of perovskites absorber layer as a function of their thicknesses. Using SLME approach which is thickness dependent it has been predicted that at thicknesses above 2.56 μm and 1.39 μm of absorber layers CsPbI3 and CsPbBr3, respectively, their efficiencies obtained using SLME approach are higher compared to that obtained using Shockley-Queisser (SQ) limit. The efficiencies of CsPbI3 and CsPbBr3 absorber layers calculated using SLME approach at absorber thickness of 20 μm are obtained around 30.41% and 24.53%, respectively.

Fabrication of two-dimensional hybrid organic–inorganic lead halide perovskites with controlled multilayer structures by liquid-phase laser ablation

We proposed a novel fabrication method of layered two-dimensional lead halide perovskites by liquid-phase laser ablation. Spacings between lead halide monolayer sheets can be controlled by choosing species of organic amine additives.

A remarkable third-order nonlinear optical behavior of single-crystal bromide organic-inorganic lead halide perovskite

The optical and structural aspects of methylamine lead bromide (MAPbBr3) single crystal (SC) are investigated. Based on Kramers–Kronig (KK) equations, the optical and dielectric parameters are investigated. The optical phonons Longitudinal optical (LO = 678 cm−1) and Transversal optical (TO = 578 cm−1) phonon modes are associated with the optical interaction with lattices in the visible region for MAPbBr3 SC. The Z-scan method is used to investigate the third-order nonlinear coefficients of SC hybrid organic–inorganic lead halide perovskites, MAPbBr3 with the 2.19 eV optical band gap energy. According to the nonlinear optical (NLO) properties, MAPbBr3 has a high third-order NLO response. The two-photon absorption (2PA) coefficient is found to be 3 × 10-4 cm W−1 using the transmission open aperture Z-scan technique. The nonlinear refraction (NLR) is obtained in the order of 10-9 cm2 W−1 utilizing a close aperture Z-scan, which revealed self-defocusing phenomena. This research shows that MAPbBr3 is a practical and low-priced nonlinear material for ultrafast photonics applications.

Effect of Dimensionality on Photoluminescence and Dielectric Properties of Imidazolium Lead Bromides.

Hybrid organic–inorganic lead halide perovskites have emerged as promising materials for various applications, including solar cells, light-emitting devices, dielectrics, and optical switches. In this work, we report the synthesis, crystal structures, and linear and nonlinear optical as well as dielectric properties of three imidazolium lead bromides, IMPbBr3, IM2PbBr4, and IM3PbBr5 (IM+ = imidazolium). We show that these compounds exhibit three distinct structure types. IMPbBr3 crystallizes in the 4H-hexagonal perovskite structure with face- and corner-shared PbBr6 octahedra (space group P63/mmc at 295 K), IM2PbBr4 adopts a one-dimensional (1D) double-chain structure with edge-shared octahedra (space group P1̅ at 295 K), while IM3PbBr5 crystallizes in the 1D single-chain structure with corner-shared PbBr6 octahedra (space group P1̅ at 295 K). All compounds exhibit two structural phase transitions, and the lowest temperature phases of IMPbBr3 and IM3PbBr5 are noncentrosymmetric (space groups Pna21 at 190 K and P1 at 100 K, respectively), as confirmed by measurements of second-harmonic generation (SHG) activity. X-ray diffraction and thermal and Raman studies demonstrate that the phase transitions feature an order–disorder mechanism. The only exception is the isostructural P1̅ to P1̅ phase transition at 141 K in IM2PbBr4, which is of a displacive type. Dielectric studies reveal that IMPbBr3 is a switchable dielectric material, whereas IM3PbBr5 is an improper ferroelectric. All compounds exhibit broadband, highly shifted Stokes emissions. Features of these emissions, i.e., band gap and excitonic absorption, are discussed in relation to the different structures of each composition.

Revealing the ground‐state geometry, optoelectronic, mechanical and thermodynamic behaviors, and efficiency of formamidinium mixed halide perovskites for solar cell applications

Hybrid organic-inorganic lead halide perovskites are the revolutionary materials that have brought a new era of low-cost and highly efficient solar cells. Generally, high-performing perovskite solar cells incorporate formamidinium-based lead halide perovskites. Using density functional theory, we employed generalized gradient approximation (GGA) and meta-GGA (MGGA) exchange-correlation functionals to investigate the structural, electronic, optical, mechanical, and thermodynamic properties of the perovskite series FAPbI3, FAPbBr2I, FAPbBrI2, and FAPbBr3. Both the functionals successfully determined the most stable structure for each mixed halide perovskite. Electronic properties such as band structure, the density of states, and effective masses have been calculated and discussed. Our estimated band gap values using MGGA functional are more close to the experiments than PBE. Optical properties of the perovskite series such as dielectric function, complex refractive index, absorption coefficient, and reflectivity have been explained in the light of photovoltaic applications. Moreover, we predicted the maximum absorber efficiency via the spectroscopic limited maximum efficiency method. FAPbI3 achieved the highest efficiency by virtue of its suitable band gap and maximum absorption. Mechanical properties have also been studied through elastic constants, elastic moduli, Pugh ratio, Poisson ratio, and other several properties, which reveal the declining flexibility of perovskites with bromine. Further, thermodynamic properties like heat capacity, Debye temperature, vibrational internal energy, vibrational entropy, thermal expansion, and thermal stability have been discussed and analyzed. Among all perovskites, the thermodynamic stability of FAPbBr2I is found superior due to strong Br-I bonds and the tougher attraction of the ionic system in the perovskite lattice. All the results are compared with earlier reported values and found to be in fair agreement.

Photoinduced large polaron transport and dynamics in organic–inorganic hybrid lead halide perovskite with terahertz probes

Organic-inorganic hybrid metal halide perovskites (MHPs) have attracted tremendous attention for optoelectronic applications. The long photocarrier lifetime and moderate carrier mobility have been proposed as results of the large polaron formation in MHPs. However, it is challenging to measure the effective mass and carrier scattering parameters of the photogenerated large polarons in the ultrafast carrier recombination dynamics. Here, we show, in a one-step spectroscopic method, that the optical-pump and terahertz-electromagnetic probe (OPTP) technique allows us to access the nature of interplay of photoexcited unbound charge carriers and optical phonons in polycrystalline CH3NH3PbI3 (MAPbI3) of about 10 μm grain size. Firstly, we demonstrate a direct spectral evidence of the large polarons in polycrystalline MAPbI3. Using the Drude–Smith–Lorentz model along with the Frӧhlich-type electron-phonon (e-ph) coupling, we determine the effective mass and scattering parameters of photogenerated polaronic carriers. We discover that the resulting moderate polaronic carrier mobility is mainly influenced by the enhanced carrier scattering, rather than the polaron mass enhancement. While, the formation of large polarons in MAPbI3 polycrystalline grains results in a long charge carrier lifetime at room temperature. Our results provide crucial information about the photo-physics of MAPbI3 and are indispensable for optoelectronic device development with better performance.

Multilevel halide perovskite memristors based on optical & electrical resistive switching effects

With the aim of addressing the growing challenge of approaching the end of Moore's law and von Neumann bottleneck, the evolution of neuromorphic computing based on memristors that emulate the behaviors of the brain has attracted great attention. Organic-inorganic hybrid lead halide perovskites with inherent hybrid ionic-electronic conduction ability have been proposed as promising candidates for memristors to replace traditional charge-based memory. Here we propose MA0.85Cs0.15PbI3 memristors with high surface crystallinity and stable operation in the atmospheric environment by mixing inorganic cation Cs+ and organic cation MA+. The prepared memristors present excellent resistive switching performances including low operation voltage, high ON/OFF ratio, stable endurance, long retention, and robustness under ambient condition. Besides that, four distinct resistance states have been obtained in the above devices by modifying the operation voltages. Moreover, the resistance switching processes can be controlled both by electrical field and light illumination. Finally, this research provides utilization potentiality in the optical and electrical two-dimension controlled multilevel information devices with a total of five stable resistance states. The present work would offer an effective way to develop multifunctional high-density data-storage applications by storing multiple resistance states in a single unit cell.

Temperature-Dependent Raman Studies of FAPbBr3 and MAPbBr3 Perovskites: Effect of Phase Transitions on Molecular Dynamics and Lattice Distortion

Three-dimensional hybrid organic–inorganic lead halide perovskites are promising photovoltaic and light-emitting materials. A key phenomenon relevant for their optoelectronic applications is electron–phonon coupling. Since it can be strongly modified by structural deformation and changes in the dynamics of molecular cations, it is of great importance to study the temperature dependence of phonon properties of hybrid perovskites. In this work, temperature-dependent Raman scattering studies of FAPbBr3 and MAPbBr3 single crystals are reported in the 1800–22 cm−1 and 300–90 K ranges. The Raman data of MAPbBr3 showed clear anomalies near 236, 155 and 148 K, which were attributed to Pm3¯m→I4/mcm→P4/mmm (or Imma)→Pnma phase transitions. They also provided strong evidence that crystal structure of the phase stable in the 155–148 K range is very similar to structure of the I4/mcm phase, not structure of the lowest-temperature Pmna phase, as suggested in some reports. Therefore, the symmetry of this phase seems to be more likely P4/mmm rather than Imma. An analysis of the temperature evolution of MAPbBr3 Raman modes revealed that the phase transitions near 236 and 155 K are associated with weak distortion of the inorganic subnetwork and changes in the dynamics of MA+ ions. Very pronounced changes in the lattice modes region and a narrowing of bands below 148 K indicated that the phase transition to the Pnma phase is triggered by a freezing of MA+ motions, which in turn leads to strong distortion of the inorganic subnetwork. Raman studies of FAPbBr3 showed that this material behaves in a very different way than MAPbBr3. First of all, the molecular dynamics of FA+ cations are not frozen even in the lowest-temperature Pnma phase. Moreover, the distortion of the inorganic subnetwork is small in the Pnma phase. The observation of weak anomalies in the lattice modes region confirmed, however, that the two crystallographically resolved phase transitions (Pm3¯m→P4/mbm near 260 K and P4/mbm→Pnma near 150 K) lead to weak distortion of the inorganic subnetwork. On the other hand, an analysis of FA+ internal modes indicated that these transitions, as well as two other crystallographically unresolved transitions near 120 and 180 K, are triggered by a change of FA+ dynamics.

Centimeter-sized lead-free iodide-based hybrid double perovskite single crystals for efficient X-ray photoresponsivity.

Hybrid organic-inorganic lead halide perovskites (HOIPs) possess significant photoelectric characteristics for solar energy conversion, but the presence of lead causes issues for eco-friendly applications. Halide double perovskites represent a green option for application in the optoelectronic field, especially X-ray detection systems. Despite the great efforts, the exploration of large-size lead-free iodide-based hybrid double perovskite single crystals for X-ray detection has been unsuccessful. Herein, we demonstrate that a large single crystal of the 2D (two-dimensional) semiconducting perovskite (C6H16N2)2CuBiI8·0.5H2O can serve as an X-ray detection candidate. A perovskite crystal, as large as 35 × 31 × 3 mm3, was grown using a low-cost, simple cooling solution approach. To the best of our knowledge, this is the first time a centimeter-sized 2D BiCu iodide double perovskite single crystal has been used for X-ray detection. The perovskite crystal exhibited unique properties for X-ray detection, such as a significant X-ray absorption coefficient, considerable μτ product, and low trap density. Moreover, X-ray detection with a sensitivity of 5.51 μC Gyair-1 cm-2 was achieved based on a single crystal. This work opens new ways to explore specially designed organic cations for stabilizing 2D HOIPs that show great potential in optoelectronics.