Hybrid Perovskite Materials Research Articles

Formamidinium Incorporates into Rb‐based Non‐Perovskite Phases in Solar Cell Formulations

AbstractOrganic‐inorganic hybrid perovskite materials, such as formamidinium lead iodide (FAPbI3), are among the most promising emerging photovoltaic materials. However, the spontaneous phase transition from the photoactive perovskite phase to an inactive non‐perovskite phase complicates the application of FAPbI3 in solar cells. To remedy this, alkali metal cations, most often Cs+, Rb+ or K+, are included during perovskite synthesis to stabilize the photoactive phase. The atomic‐level mechanisms of stabilization are complex. While Cs+ dopes directly into the perovskite lattice, Rb+ does not, but instead forms an additional non‐perovskite phase, and the mechanism by which Rb confers increased stability remains unclear. Here, we use 1H−87Rb double resonance NMR experiments to show that FA+ incorporates into the Rb‐based non‐perovskite phases (FAyRb1‐yPb2Br5 and δ‐FAyRb1‐yPbI3) for both bromide and iodide perovskite formulations. This is demonstrated by changes in the 1H and 87Rb chemical shifts, 1H−87Rb heteronuclear correlation spectra, and 87Rb{1H} REDOR spectra. Simulation of the REDOR dephasing curves suggests up to ~60 % FA+ incorporation into the inorganic Rb‐based phase for the bromide system. In light of these results, we hypothesize that the substitution of FA+ into the non‐perovskite phase may contribute to the greater stability conferred by Rb salts in the synthesis of FA‐based perovskites.

Formamidinium Incorporates into Rb-based Non-Perovskite Phases in Solar Cell Formulations.

Organic-inorganic hybrid perovskite materials, such as formamidinium lead iodide (FAPbI3), are among the most promising emerging photovoltaic materials. However, the spontaneous phase transition from the photoactive perovskite phase to an inactive non-perovskite phase complicates the application of FAPbI3 in solar cells. To remedy this, alkali metal cations, most often Cs+, Rb+ or K+, are included during perovskite synthesis to stabilize the photoactive phase. The atomic-level mechanisms of stabilization are complex. While Cs+ dopes directly into the perovskite lattice, Rb+ does not, but instead forms an additional non-perovskite phase, and the mechanism by which Rb confers increased stability remains unclear. Here, we use 1H-87Rb double resonance NMR experiments to show that FA+ incorporates into the Rb-based non-perovskite phases (FAyRb1-yPb2Br5 and δ-FAyRb1-yPbI3) for both bromide and iodide perovskite formulations. This is demonstrated by changes in the 1H and 87Rb chemical shifts, 1H-87Rb heteronuclear correlation spectra, and 87Rb{1H} REDOR spectra. Simulation of the REDOR dephasing curves suggests up to ~60 % FA+ incorporation into the inorganic Rb-based phase for the bromide system. In light of these results, we hypothesize that the substitution of FA+ into the non-perovskite phase may contribute to the greater stability conferred by Rb salts in the synthesis of FA-based perovskites.

Performance optimization of MA0.5FA0.5PbI3/CsPbI3 based hybrid perovskite solar cell emphasizing on double absorber layer

Abstract The utilization of cesium-based lead halide (CsPbI3) PSC has considerable potential in the photovoltaic industry due to their high efficiency, underpinned by features such as a high absorption coefficient, thermal stability, and commendable efficiency. Nevertheless, the bandgap of CsPbI3, standing at 1.7 eV, poses a challenge as it is relatively high for a single-junction device. To overcome this limitation, we introduced a dual absorber layer structure by interleaving CsPbI3 with a lead-based hybrid perovskite material, denoted as MA0.5FA0.5PbI3. This investigation focused on the MA0.5FA0.5PbI3/CsPbI3 hetero-junction structure to ascertain the maximum possible efficiency. Therefore, this study proposed a PSC with the configuration of Ag/MoO3/MA0.5FA0.5PbI3/CsPbI3/IGZO/Au. In this setup, MoO3 (Molybdenum Trioxide) is used as the HTL and IGZO (Indium Gallium Zinc Oxide) as the ETL. Silver (Ag) serves as the back contact and gold (Au) is the front contact. This device demonstrated remarkable characteristics with Voc = 1.307 V, Jsc = 22.71 mA cm−2, FF = 86.58%, and η = 26.21%, showcasing a substantial improvement compared to previously reported CsPbI3-based homojunction PSCs. Furthermore, this study delved into the effects of absorber doping, absorber material thickness, bulk defect, and interfacial defects on solar cell parameters to obtain high-performance solar cells.

Recent Advances in Organic Photodetectors

Organic photodetectors (OPDs) have garnered significant attention in fields such as image sensing, health monitoring, and wearable devices due to their exceptional performance. This review summarizes recent research advancements in materials, structures, performance, and applications of narrowband organic photodetectors, hybrid organic–inorganic perovskite photodetectors, flexible organic photodetectors (FOPDs), and photomultiplication type organic photodetectors (PM-OPDs). Organic semiconductors offer substantial potential in optoelectronic devices owing to their low cost, ease of processing, and tunable spectral response. Hybrid perovskite materials extend the spectral response range, FOPDs meet the demands of wearable devices, and PM-OPDs enhance sensitivity, allowing for the detection of weak light signals. Through innovations in materials, structural optimization, and improvements in manufacturing processes, the performance of OPDs has seen significant enhancement. This article also explores the application prospects of these technologies in medical monitoring, optical communications, and image sensing.

Determination of the particle size distribution of cube-shaped colloidal perovskite quantum dots from photoluminescence spectra: A combined theoretical-experimental approach.

A theoretical-experimental approach is proposed to convert the photoluminescence spectra of colloidal perovskite quantum dot ensembles into accurate estimates for their intrinsic particle size distribution functions. Two main problems were addressed and properly correlated: the size dependence of the first excitonic transition in a single cube-shaped quantum dot and the inhomogeneous broadening of the fluorescence line shape due to the size nonuniformity of the chemically prepared quantum dot suspension in addition to the single-dot homogeneous broadening. By applying the reported methodology to CsPbBr3 quantum dot samples belonging to the strong and intermediate confinement regimes, the calculated size distributions exhibited close agreement with those obtained from transmission electron microscopy, with precise estimates for the average particle size and standard deviation. Specifically for strongly confined ultrasmall CsPbBr3 quantum dots, the presented spectroscopic model for size distribution computation is based on a new analytical expression for the size-dependent bandgap, which was developed within the framework of the finite-depth square-well effective mass approximation accounting for band nonparabolicity effects. Such a quantum mechanical approach correctly predicts the expected transition to the intermediate confinement regime in sufficiently large quantum dots, which are traditionally described by the well-known bandgap equation in the infinite potential barrier limit with a spatially correlated electron-hole wavefunction and nonparabolic carrier effective masses. The proposed calculation scheme originates from general theoretical considerations so that it can be readily adapted to semiconductor quantum dots of many other systems, from all inorganic metal halides to hybrid perovskite materials, regardless of the adopted chemical synthesis route.

Polar Alternating Cations Intercalated Hybrid Perovskite with Iodine‐Substituted Spacers Toward Efficient Passive X‐Ray Detection

Abstract2D hybrid perovskites, with their high X‐ray absorption and extended carrier transport, present excellent promise for efficient direct X‐ray detection. However, most of the current devices require external bias voltage, which results in the need for significant energy consumption and severe ion migration, therefore, it is urgent to develop new types of materials for achieving efficient passive X‐ray detection. Herein, two novel chiral polar alternating cations intercalation (ACI)‐type hybrid perovskite materials, named (R/S‐PPA)(IEA)PbBr4 (1‐R/S, (R/S)‐PPA = R/S‐1‐phenylpropylamine; IEA = iodoethylamine), are constructed by integrating the chiral aromatic spacer R/S‐PPA and the iodine‐substituted spacer IEA. Various intermolecular interactions, such as I···I, C─H···I, π···π interactions, are introduced due to the introduction of I‐substituted chain amines, which effectively suppresses ion migration and thus lead to improved operational stability. The device constructed along the polar axis displays superior X‐ray detection performance, such as relatively high sensitivity and an ultra‐low limit of detection (LoD) of 3.0 nGy s−1, making it the first chiral ACI‐type perovskite material for realizing efficient passive X‐ray detection. Furthermore, 1‐R also presents low dark current drift and exceptional irradiation stability. This work provides new thought for using novel ACI‐type polar perovskite for high‐performance passive direct X‐ray detection.

Ab initio study of surfaces of lead and tin based metal halide perovskite structures

Abstract Hybrid perovskite materials, known for their potential in cost-effective optoelectronic applications, face a knowledge gap in crucial areas, particularly the atomic-level properties of the surface. This study addresses this challenge by refining ab initio methods for characterizing surface structures of cubic methylammonium lead bromide and methylammonium tin bromide (MAMeBr3 with Me = Sn, Pb), avoiding superficial restrictions in atomic movement during geometry optimization. The resulting structures confirmed nearly random MA+ molecule alignment, comparable to real-world experimental conditions. Calculating surface energies for these structures with crystal orientations {100} and {110}, each with different terminations, provides valuable insights into structural properties. Using a carefully chosen thermodynamic reference state, mimicking experimental conditions enables a thermodynamic discussion and facilitates the modulation of the MeBr2 component’s chemical potential. This modulation, in turn, allows for the prediction of crystal morphologies, as illustrated by Wulff’s construction. This approach establishes a crucial link between theoretical predictions and experimental conditions, shedding light on the complexities of hybrid perovskite materials.

Chalcogenide perovskite BaZrS3 bulks for thermoelectric conversion with ultra-high carrier mobility and low thermal conductivity

Chalcogenide perovskites are expected to be promising thermoelectric materials, since they not only possess efficient carrier transport and defect tolerance, but also demonstrate unique advantages of high thermodynamic stability, eco-friendly and earth-abundant constituents. Especially, theoretical reports have predicted their “glass-like” thermal conductivities. However, experimental investigation on thermoelectric performances of chalcogenide perovskite BaZrS3 is extremely scarce due to the difficulty in preparing high-quality bulk samples, which originates from the brittle nature, high melting point, and the large difference in melting points between Ba/S and Zr. In this work, pure phase BaZrS3 bulks with high relative density reaching 100 % are realized by optimized sulfurization from low-cost BaZrO3 powders combined with fast spark plasma sintering. A maximum zT value of 0.37 at 623 K in BaZrS3 bulks is achieved, which is the record-high value among the reported sulfide, halide, and hybrid perovskite materials. A room-temperature electron mobility up to 385 cm2V−1s−1 is among the highest values for perovskites due to the high phase purity, dense morphology and corner-sharing ZrS6 octahedral three-dimensional network as effective carrier channels. Meanwhile, a measured low lattice thermal conductivity of 1.11 Wm−1K−1 at 623 K is attributed to the intense phonon scattering from the intrinsic distorted-perovskite structure and the lattice defects by sulfur deficiency. Moreover, the BaZrS3 bulks in this work are stable against moisture/air and high temperature test. This work provides new insights into the fundamental electrical and thermal properties of chalcogenide perovskites, and highlights their great potential in the practical thermoelectric applications.

Controlling structural, electronic and optical properties of cubic FASnI3 perovskites using biaxial strains in the presence of spin orbit coupling: A DFT analysis

There is a significant research focus on the utilization of organic-inorganic hybrid perovskite materials in the field of photovoltaics. The remarkable electronic and optical characteristics of organic-inorganic hybrid perovskites are prevalent in solar applications. In this study, the first-principles density functional theory (DFT) was used to investigate how strains affect the structural, electronic, and optical properties of the formamidinium tin tri-iodide (hereafter FASnI3) perovskite structure. The band structure analysis revealed that FASnI3 possesses semiconductor properties. A direct bandgap of 0.96 eV was found at the R-point for unstrained planar FASnI3 structure. The bandgap was reduced when compressive strains were applied. In contrast, the bandgap attained a higher value due to the increased tensile strains. Moreover, the optical properties, such as absorption coefficient, dielectric function and electron loss function, showed that FASnI3 structures have good photo-absorption ability. The dielectric constant exhibited a redshift in its peaks as the compressive strains were increased. However, the dielectric peaks exhibited a blueshift when subjected to the tensile strains. Additionally, for a deeper understanding of the band structure, the effect of spin-orbit coupling (SOC) was considered. The band gap of the FASnI3 perovskite structure was 0.75 eV when the SOC effect was considered. The strain is a crucial factor to consider for optimizing the performance of FASnI3 perovskite structure for their applications in optoelectronic devices.

Exploring the potential applications of lead-free organic–inorganic perovskite type [NH3(CH2)nNH3]MCl4 (n = 2, 3, 4, 5, and 6; M = Mn, Co, Cu, Zn, and Cd) crystals

The organic–inorganic hybrid perovskite compounds have been extensively studied since the dawn of a new era in the field of photovoltaic applications. Up to now, perovskites have proven to be the most promising in terms of power conversion efficiency; however, their main disadvantages for use in solar cells are toxicity and chemical instability. Therefore, it is essential to develop a hybrid perovskite that can be replaced with lead-free materials. This review focuses on the possibility of applying lead-free organic–inorganic perovskite types [NH3(CH2)nNH3]MCl4 (n = 2, 3, 4, 5, and 6; M = Mn, Co, Cu, Zn, and Cd) crystals. We are seeking organic–inorganic hybrid perovskite materials with very high temperature stability or without phase transition temperature, and thermal stability. Thus, by considering the characteristics according to the methylene lengths and the various transition metals, we aim to identify improved materials meeting the criteria mentioned above. Consequently, the physicochemical properties of organic–inorganic hybrid perovskite [NH3(CH2)nNH3]MCl4 regarding the effects of various transition metal ions of the anion and the methylene lengths of the cation are expected to promote the development and application of lead-free hybrid perovskite solar cells.

Unraveling the Heat- and UV-Induced Degradation of Mixed Halide Perovskite Thin Films via Surface Analysis Techniques.

In recent years, organic-inorganic hybrid perovskite materials have become one of the most promising materials in the new generation of solar cells. These perovskites can provide excellent photoelectric properties after a simple fabrication process. Although perovskite solar cells have achieved high power conversion efficiency, instability concerns regarding material exposure to heat, moisture, air, and UV light present hindrances to commercialization. In this study, three kinds of perovskites (MAPbI3, MAPbI3-xBrx, and MAPbI3-xClx) were used to investigate the crystal stability upon exposure to heat and UV light. SEM, XRD, and FTIR were used to observe the surface morphology, crystal structure, and functional groups of the perovskite thin films. XPS was used to examine the surface composition and chemical state of the perovskite thin films under different conditions. Among these three types of perovskites, it was found that the MAPbI3-xBrx crystal demonstrated the best stability. ToF-SIMS was used to confirm the molecular distribution of the MAPbI3-xBrx films upon exposure to heat and UV light at different depths. ToF-SIMS revealed that [Pb]+ and [PbI]+ aggregated at the interface between the perovskite and ITO substrate after 14 days of thermal treatment. On the other hand, [Pb]+ and [PbI]+ were distributed uniformly after 3 days of UV exposure. This study systematically analyzed and revealed the thermal- and UV-induced degradation process of three perovskite films by using surface analysis techniques. It was concluded that bromine-doped perovskite films had better stability, and UV light caused more severe damage than heat.

Effects of valence changes of iodine on perovskite (CH3NH3PbI3) Raman

In recent years, organic–inorganic hybrid perovskite materials have garnered extensive attention from scholars. Given its high absorption coefficient, carrier mobility, and diffusion length, it is widely studied for applications in various optoelectronic devices, such as solar cells, photodetectors, field-effect transistors, and light emitting diodes. Among them, the interfacial charge transfer process is a key factor influencing the performance of devices using perovskite materials. The charge transfer (CT) at the interface is typically detected via Raman spectroscopy. There are three types of related CT processes, namely, the interfacial ground state charge transfer, the photoinduced charge transfer resonance, and the electronic excitation resonance within the molecule itself. Among these factors, electronic excitation resonance manifests as an exciton resonance within the perovskite structure, providing energy for nearby charge transfer, thereby promoting charge transfer and enhancing Raman signals. Therefore, enhancing exciton resonance within the perovskite structure plays a crucial role in optoelectronic devices. This paper aimed to study the mechanism of oxygen plasma passivation of interstitial iodine defects and its enhancement effect on the Raman of perovskite substrates. Typically, interstitial iodine defects induce electron–hole recombination. In the process of oxygen plasma treatment, interstitial iodine is converted into pentavalent iodine, which can effectively fill related defects, inhibit electron–hole recombination, and prolong exciton lifetime, thereby promoting charge transfer and enhancing Raman intensity.

Fine optimized cation immobilization strategy for enhancing stability and efficiency of perovskite solar cells

The migration and volatilization of cations within organic–inorganic hybrid perovskite (OIPs) materials has been identified as a major issue for irreversibly degrading perovskite solar cells (PSCs), severely limiting their performance and impeding progress toward large-scale applications. To mitigate these problems, an adjustable cation immobilization strategy was proposed for the first time, in which a series of fluorobenzenesulfonamide (FBSA) molecules was introduced into perovskite precursor, a strong coordination bond was formed between the sulfonamide group with the octahedral imperfection caused by iodine vacancy, along with a hydrogen bond formed between the cation and F atom. As a result, the A-site cations were tightly immobilized in the octahedral of perovskite crystal lattice and the uncoordinated Pb2+ defects were effectively eliminated. Besides, the immobilization distance of cation was finely optimized by changing the substitution position of F atoms. Based on the cation-immobilized perovskite film, the efficiency of PSCs was significantly increased from 19.88 % to 22.30 %. Moreover, the unencapsulated PSCs exhibited impressive light and thermal stability, retaining 82 % of the initial efficiency after 720 h illumination at 1-sun, and maintaining nearly 80 % of the initial PCE after heating at 85 °C for 240 h. Thus, the present study offers a promising approach for advancing the commercialization of stable and high-efficiency perovskite solar cells.

MAPbI3 perovskite photodetectors for high-performance optical wireless communication

High-sensitivity and fast-response photodetectors (PDs) are vital part of optical wireless communication (OWC) system. In this work, we develop an organic–inorganic hybrid perovskite material (MAPbI3) based p–i–n structured PD. By optimizing the precursor solution concertation, the PD showed a high responsivity of 0.98 A W−1, a fast response time t rise/t fall of 12/12.5 μs, a specific detectivity of 2.62 × 1013 Jones, and the f−3dB of 24 kHz under the 532 nm laser and −0.2 V bias voltage. Furthermore, we designed an OWC system based on the prepared PD. With the baud rate of 19200 bps, the system exhibits a bit error rate less than 10−6, and it can realize 9.63 m long-distance communication and quick transmission applications such as strings, texts, photos, and audios. Our work demonstrates the great application potential of perovskite PDs in the field of optical communication.

Structural phase transition in a new organic-inorganic hybrid post-perovskite: (N,N-dimethylpyrrolidinium)[Mn(N(CN)2)3]

In the realm of molecular phase transition research, particularly for applications in sensors, data storage and switching technologies, the role of organic-inorganic hybrid perovskite materials has been increasingly recognized for their significant potential. Nevertheless, hybrid post-perovskites, as a critical subclass of perovskites, have not been thoroughly studied and mainly limit in the instances based on polyatomic bridging agents like dicyanamide (dca−) and non-cyclic organic cations. Herein, a polar cyclic quaternary ammonium cation, N,N-dimethylpyrrolidinium (DMP+), was used to assemble a new hybrid post-perovskite, (DMP)[Mn(dca)3] (1), which undergoes a phase transition from orthorhombic Bmmb to monoclinic P21/n space group at 249 K. By employing multiple techniques such as differential scanning calorimetry, variable-temperature single-crystal X-ray analysis, dielectric measurements, and Hirshfeld surface analysis, we disclosed the role of polar cyclic quaternary ammonium DMP+ in elevating the phase-transition temperature by 48 K, generating significant dielectric switching effect and facilitating interlayer sliding of inorganic framework.

Band gap engineering and enhanced optoelectronic performance by varying dopant concentration in RbSr[formula omitted]Sn[formula omitted]Cl[formula omitted]: Ab-inito study

In the pursuit of eco-friendly solar cells, the exploration of lead-free perovskite halides has gained momentum. This study examines tin (Sn) doping effects on RbSrCl3, a lead-free perovskite, using density functional theory (DFT). Systematically varying Sn doping (25%, 50%, 75%, 100%), the research reveals consistent mechanical stability of the doped systems. Notably, an inverse relationship emerges: increased Sn dopant reduces bandgap values, enhancing visible range absorption of the hybrid perovskite materials which is crucial for solar efficiency. Extending simulations to 14 eV, optical properties like refractive index, absorption coefficient, and conductivity are explored offering a comprehensive understanding of the materials’ optical behavior. In summary, Sn-doped hybrid perovskite materials exhibit both mechanical stability and tunable optoelectronic properties, positioning them as promising candidates for solar cell technology. The study is a significant step in advancing environmentally conscious solar cell technologies for sustainable energy applications.

Hydrogen Bonds in Perovskite for Efficient and Stable Photovoltaic†

Comprehensive SummaryOwing to their distinctive optical and physical properties, organic‐inorganic hybrid perovskite materials have gained significant attention in the field of electronic devices, especially solar cells. The achievement of high‐performance solar cells hinges upon the utilization of top‐notch perovskite thin films. Nevertheless, the fabrication process involving solutions and the polycrystalline nature of perovskite result in the emergence of numerous defects within the perovskite films, consequently exerting a deleterious influence on the overall performance and stability of the devices. Improving the performance and stability of perovskite solar cells by additive engineering to suppress/passivate defects is a viable approach, which involves hydrogen bond interactions in these device engineering processes. This review explores the intrinsic hydrogen bonds in methylammonium and formamidium lead triiodide, while also considering cation rotations, phase transitions, and stability. Moreover, the review classifies additives into distinct categories, including organic small molecules, polymers, nanodots, classical salts, ionic liquids, and molten salts. The various forms and characterization techniques of hydrogen bonds are discussed, as well as their potential synergistic effects in conjunction with other chemical interactions. Furthermore, this review offers insights into the potential utilization of hydrogen bonds to further enhance the performance and stability of devices. Key ScientistsIn 2009, Tsutomu Miyasaka et al. prepared the first perovskite solar cell, which kicked off the research on perovskite light‐absorbing materials. However, the use of liquid electrolytes led to device instability. The transition to all‐solid‐state perovskite solar cells was realized by Nam‐Gyu Park's team in 2012, which was the beginning of high‐efficiency perovskite solar cells. Subsequently, a number of scientists have innovated the preparation ground process. Methods such as two‐step deposition by Michael Grätzel in 2013 and anti‐solvent extraction by Sang II Seok's team in 2014 were instrumental in advancing the development of perovskite. Liyuan Han's team then increased the cell's working area to 1 cm2 without compromising performance, making it possible to compare the performance metrics of perovskite solar cells with those of other types of solar cells on the same scale. Recently, You's team and Pan's team kept updating the world record by obtaining certified efficiencies of 25.6% and 25.8% in 2022 and 2023, respectively.

Comparing Charge Dynamics in Organo-Inorganic Halide Perovskite: Solid-State versus Solid-Liquid Junctions

In this study, we explore the dynamics of a perovskite-electrolyte photoelectrochemical cell, pivotal for advancing electrolyte-gated field effect transistors, water-splitting photoelectrochemical and photocatalytic cells, supercapacitors, and CO2 capture and reduction technologies. The instability of hybrid perovskite materials in aqueous electrolytes presents a significant challenge, yet recent breakthroughs have been achieved in stabilizing organo-inorganic halide perovskite films. This stabilization is facilitated by employing liquid electrolytes, specifically those formed by dissolving tetrabutylammoniumperchlorate in dichloromethane. A critical aspect of this research is the comparative analysis of charge and ion kinetics at the perovskite/liquid electrolyte interface versus the perovskite/solid charge transport layer interface. Employing Intensity Modulated Photocurrent Spectroscopy (IMPS), Open-Circuit Voltage Decay (OCVD), and Capacitance-Frequency (C-F) methods, the study scrutinizes charge dynamics in both perovskite/electrolyte and perovskite/solid interfaces. Furthermore, the investigation extends to contrasting the properties of solid–liquid and solid-state junctions, focusing on mobile ions, electric field impacts, and electron-hole transport. The research also examines variations in recombination resistance and ionic double layer charging in perovskite-based devices, aiming to elucidate the operational mechanisms and kinetic complexities at the hybrid perovskite/electrolyte interface.

Recent advances of computational simulation on polarons in organic-inorganic hybrid perovskites

Organic-inorganic hybrid perovskites are prized for their exceptional properties and ease of use, finding applications in high-efficiency, cost-effective solar cells. Hybrid perovskite materials, belonging to the perovskite family, possess unique crystallographic and electronic structures that benefit from versatile phase transitions and component modifications. The crystal structure and electronic characteristics of perovskites facilitate the generation of polarons, which are quasiparticles that readily form in organic-inorganic hybrid perovskites due to the coupling of excess electrons or holes to ionic vibrations and play a pivotal role in shaping the electronic properties. This review delves into the polarons within organic-inorganic hybrid perovskites, in which the formation and interaction of polarons within the crystal lattice and their profound impact on material properties. Computational simulations offer insights into polaron characteristics, such as phonon density of states, carrier-phonon coupling, and polaron dynamics. Therefore, it is of vital importance to make clear the fundamental properties focusing on polarons in perovskite, since a comprehensive understanding of them would significantly facilitate the enhancement of the electronic and optoelectronic characteristics, and eventually contribute to the release of their full potential in real-world applications

THz‐Wave Absorption Properties of Organic–Inorganic Hybrid Perovskite Materials: A New Candidate for THz Sensors

Over the past two decades, organic–inorganic hybrid perovskite materials (OHP) have been extensively explored across various scientific disciplines, including physics, chemistry, and materials science, with a primary focus on solar cells. Building on numerous studies, the development of OHP‐based solar cells has transitioned into practical product realization, instilling the anticipation of novel solar cell advancements. Notably, OHP demonstrates versatility beyond its conventional application in solar cell materials. The physical properties of OHP materials exhibit a unique signature, thereby underscoring their potential utility as innovative functional materials, encompassing light‐emitting diodes, lasers, and photodetectors. Recent reports on terahertz (THz)‐wave absorption properties of OHP materials indicate a high possibility of their potential application as THz sensors. From the viewpoint of medical devices, which hold the most promising application potential, the exploration of optical phonon vibrational modes in the 0.5–3 THz frequency range is important. Moreover, understanding the correlations between atomic structure and lattice vibration modes is indispensable. In this concise review, the THz‐wave absorption properties exhibited by 3D OHP materials are meticulously explored. Furthermore, future research directions for THz sensors using OHP materials are suggested.