Carrier Mobility Research Articles

Opto-electrical study of 4T perovskite-chalcogenide tandem solar cell with the addition of quasi-2D perovskite as capping layer of 3D perovskite layer

This study presents a four-terminal (4T) perovskite-chalcogenide tandem solar cell (TSC) that includes quasi-2D perovskite material in the top sub-cell in order to provide a stable structure, and the bottom sub-cell contains Zn(O,S,OH) material to provide a nontoxic buffer layer. First, a reference TSC with a total power conversion efficiency (PCE) of 26.48% is modeled, using MAPbI3 and CIGSSe as 3D perovskite and chalcogenide absorber layers (ALs), respectively. Next, two structures are designed to produce a stable SC using the Ruddlesden Popper (RP) quasi-2D perovskite materials, which have the chemical formula BA2MAm−1PbmI3m+1, m = 2–5. The initial structure uses quasi-2D perovskites in place of the 3D perovskite AL. According to the results, BA2MAPb2I7 represents the maximum PCE of 16.00%, 10.48% less than previously. This is caused by quasi-2D materials’ high Eg and low carrier mobility. In the second structure, 3D perovskite AL is capped with the quasi-2D perovskites. In terms of attaining maximum PCE, the optimal TSC is found for BA2MA3Pb4I13 with a PCE of 25.80%. Compared to the initial structure, this one’s PCE increased by 61.25%. In order to boost PCE, a 80 nm-thick anti-reflection (AR) layer is added to the second structure, and the PCE increased to 27.48%. Therefore, the final TSC is proposed as a 4T quasi-2D/3D perovskite-chalcogenide TSC that is stable, and has nontoxic buffer layer, with 3.78% more PCE than the reference structure.

Enhanced Carrier Transport Performance of Monolayer Hafnium Disulphide by Strain Engineering.

For semiconducting two-dimensional transition metal dichalcogenides (TMDs), the carrier transport properties of the material are affected by strain engineering. In this study, we investigate the carrier mobility of monolayer hafnium disulphide (HfS2) under different biaxial strains by first-principles calculations combined with the Kubo-Greenwood mobility approach and the compact band model. The decrease/increase in the effective mass of the conduction band (CB) of monolayer HfS2 caused by biaxial tensile/compressive strain is the major reason for the enhancement/degradation of its electron mobility. The lower hole effective mass of the valence bands (VB) in monolayer HfS2 under biaxial compressive strain improves its hole transport performance compared to that under biaxial tensile strain. In summary, biaxial compressive strain causes a decrease in both the effective mass and phonon scattering rate of monolayer HfS2, resulting in an increase in its carrier mobility. Under the biaxial compressive strain reaches 4%, the electron mobility enhancement ratio of the CB of monolayer HfS2 is ~90%. For the VB of monolayer HfS2, the maximum hole mobility enhancement ratio appears to be ~13% at a biaxial compressive strain of 4%. Our results indicate that the carrier transport performance of monolayer HfS2 can be greatly improved by strain engineering.

Proposing lead-free Cs2SnI6-nBrn for silicon heterojunction-based tandem solar cell

Emerging Lead (Pb)-free perovskite solar cells are environment-friendly and show higher stability. Such materials are considered the future of the photovoltaic industry. However, the detailed understanding of these materials is still very limited experimentally as well as theoretically. In this work, all inorganic Pb-free perovskites Cs2SnI6-nBrn have been studied as top cell materials for silicon heterojunction (SHJ)-based tandem solar cells. The optoelectronics characteristics including bandgap, optical absorption, effective masses and carrier mobility of Cs2SnI6-nBrn have been calculated by the first-principle with varying Br- alloying. Details theoretical study show that the bandgap of Cs2SnI6-nBrn can tuned over a range of 1.05 eV to 1.99 eV. In addition, carrier mobility has been modelled for the studied perovskites by deformation potential theory. Based on the calculated optoelectronics characteristics, a standalone Cs2SnI6-nBrn solar cell is simulated and 20.5 % efficiency is reported. SHJ-based solar cell is used as the bottom cell with 28.5 % standalone efficiency under standard spectrum illuminations. Finally, the Cs2SnI6-nBrn/SHJ tandem solar cell is designed and a simulated PCE of 39.1 % has been achieved with n = 1. The highest 1.46 V Voc is obtained with a 40.5 mA/cm2 matched current between the top and bottom cells. The proposed work gives a detailed study of Cs2SnI6-nBrn perovskites and is expected to facilitate the production of Pb-free perovskites/SHJ tandem solar cells.

Synergistic impact of metal/semiconductor (Co@Co3O4) core-shell nanostructures on the structure, electrical, and dielectric properties of BaTiO3-based composites

The synergistic impact of metal/semiconductor nanostructures with controlled size and specific morphology on the structure, electrical, and dielectric properties of BaTiO3-based composites has been investigated. The conductive metal (Co) and semiconductor metal oxide (Co3O4) in the form of core-shell Co@Co3O4 nanoparticles have been used as additives for the first time in the present study. Accordingly, BaTiO3/Co@Co3O4 composite materials with different percentage ratios of 100/0 %, 98/2 %, 95/5 %, 90/10 %, 80/20 %, and 0/100 % have been developed and studied. The prepared ceramic composites were characterized via XRD, SEM, EDX, and impedance analyzer. XRD results revealed the formation of high-purity cubic BaTiO3 phase without any traces of secondary phases, as well as the formation of composite structures when Co@Co3O4 core-shell nanostructures are introduced. No diffraction peaks related to other phases are detected in the composite ceramics. According to SEM and elemental distribution analyses, the Co@Co3O4 core-shell nanoparticles are locally distributed between the BaTiO3 grains and formed 0–3 type composites. The composition- and temperature-dependent dielectric and electrical characteristics were also explored. The incorporation of Co@Co3O4 core-shell nanostructures improved both the mobility of charge carriers and charge carrier density by lowering the barriers that greatly affect polarization in ceramic composites. The electrical conductivity was higher in the composite with a BaTiO3:Co@Co3O4 ratio of 80 %:20 % in comparison to pristine BaTiO3 and other composite ceramics. The dielectric loss tangent (tan δ) is lower for composite ceramics with low additive contents. Furthermore, the resonance maximum in tan δ curves for these samples moves to higher frequencies as temperature increases. Based on Cole-Cole plots, a small and hardly visible suppressed semicircle and a flat line are observed in the studied frequency region. The angle of the semicircles upsurges as the concentration of Co@Co3O4 core-shell nanostructures increases, which can be attributed to the increased inhomogeneity in the composites. The present study may offer some new clues for understanding and developing metal/semiconductor/BaTiO3-based composites.

Bismuth niobate/g-C3N4 heterojunction for maximised visible light photocatalytic removal of Bisphenol A

The occurrence of xenobiotic pollutants in the aquatic environment troubling the present and future generation. Persistent Organic Pollutants (POPs) is one such class of xenobiotic that was dominant in that category. In the present paper, a competent visible light driven heterojunction photocatalyst combining Bismuth niobate and g-C3N4 was developed for the effective removal of Bisphenol A (BPA), a notable POP. Before constructing the heterostructure the calcination temperature for bismuth niobate synthesis was optimised for achieving most proficient photocatalysis. A phase change in the crystal structure of bismuth niobate was apparent. The Bi3NbO7 at 300–500 °C transformed to Bi5Nb3O15 at 600–700 °C and to orthorhombic BiNbO4 at 900 °C as the temperature was enhanced. With the increment in the temperature the light absorbance of the materials enhanced in UV and reduced in visible light. Thus, the bismuth niobate obtained by calcining at 500 °C demonstrated highest BPA removal under sunlight was chosen for heterojunction construction. After the heterojunction construction with g-C3N4 the crystal lattice strain was observed to be reduced for all composites, and a greater mobility of charge carriers was observed within the composite. The presence of either of the materials resulted in a different band structure and thus Type II and Z-scheme pathway was inferred. A commendable photocatalytic activity was observed for B1.5G and BG1.5 under sunlight and LED light respectively. Hight amount of g-C3N4 in the BG1.5 resulted in maximum absorbance in LED light. Superoxide radicals (*O2−) radicals were observed as major radicals for B1.5G composite, whereas both *O2− and holes (h+) were the major radicals in case of BG1.5.

Retina-Inspired Large-Area Solution-Processed flexible Multi-Band organic neuromorphic synaptic transistor arrays

The proliferation of high-efficacy, pliable organic neuromorphic synaptic transistors is quintessential for the integration into wearable artificial intelligence ecosystems. Nevertheless, their development is hindered by substantial energy demands and suboptimal charge carrier mobility. To surmount these obstacles, we exploit solution-processed poly(amic acid) (PAA) dielectrics and organic semiconductors to engineer pliable arrays of organic neuromorphic synaptic transistors atop a polyethylene terephthalate (PET) matrix. The polar group and nanogroove structure of PAA obtain excellent semiconductor crystal structure, and the excellent dielectric properties enable these engineered arrays to show a charge carrier mobility peak of 29.83 cm2 V−1 s−1 an aggregate mean mobility of 15.87 cm2 V−1 s−1 (standard deviation is 6.71) at a voltage of −3 V and the energy expenditure per synaptic transaction was only 0.26 fJ. Additionally, the transistors possess the aptitude for photodetection across ultraviolet–visible to near-infrared spectral bands. The successful execution of flexible imaging, Pavlovian classical conditioning reflex associative learning, coupled with a 93.9 % accuracy in handwritten numeral recognition, corroborates the viability of these high-mobility, low-power organic neuromorphic synaptic transistor arrays.

Enhanced Activation in Phosphorous-Doped Silicon via Dual-Beam Laser Annealing.

In this study, we conduct a comparative analysis of single-beam laser annealing (SBLA) and dual-beam laser annealing (DBLA) techniques for semiconductor manufacturing. In the DBLA approach, two laser beams were precisely aligned to simultaneously heat a phosphorus-doped silicon (Si) wafer. The main objective was to investigate the impact of the two annealing techniques on the electrical properties, crystalline structure, and diffusion profile of the treated phosphorus-doped Si at equivalent laser powers. Both SBLA and DBLA improved the electrical properties of the phosphorus-doped Si, evidenced by increased carrier concentration and reduced carrier mobility. Additionally, the crystalline structure of the phosphorus-doped Si showed favorable modifications, with no defects and improved crystallinity. While both SBLA and DBLA produced similar phosphorus profiles with no significant redistribution of dopants compared to the as-implanted sample, DBLA achieved a higher activation ratio than SBLA. Although the results suggest improved dopant activation with minimal diffusion, further studies are needed to clearly confirm the effect of DBLA on dopant activation and diffusion.

Ab inito investigation on structural, electronic, and optical characteristics of HfClI Janus monolayer

Utilizing ab initio calculations based on density functional theory, this study delves into the structural, electronic, and optical properties of the HfClI Janus monolayer. Our comprehensive analysis demonstrates the monolayer's dynamical stability, evident from the absence of negative modes in its phonon dispersion spectra. Furthermore, structural analysis reveals no significant bond disruptions or reconstructions, thereby confirming the monolayer's ability to sustain its configuration even at elevated temperatures up to 600 K. In terms of electronic structure, HSE calculations reveal an indirect band gap of 1.359 eV, which undergoes a reduction to 1.281 eV upon inclusion of spin-orbit coupling (SOC). Particularly, the HfClI Janus monolayer exhibit ultrahigh carrier mobilities, ranging from 1257 cm2/sV to 3125 cm2/sV, displaying ultrahigh carrier mobilities. Notably, the monolayer exhibits remarkable absorption capabilities spanning the visible and ultraviolet spectra, hinting at its potential for nano-optoelectronic applications, especially in the realm of electromagnetic radiation absorption and detection. These findings underscore the promising characteristics of the HfClI Janus monolayer, positioning it as a viable candidate for future technological advancements and advancements in nano-optoelectronics.

Wafer-scale N-polar GaN heterogeneous structure fabricated by surface active bonding and laser lift-off

N-polar Gallium nitride (GaN) technology is one of the most important technical routes for millimeter-wave devices. This paper introduces a new approach based on reverse epitaxial layer transfer technology to fabricate N-polar GaN materials. By combining low-damage surface-activated bonding and laser lift-off techniques, a wafer-scale N-polar GaN heterogeneous structure with low O impurities, high two-dimensional electron gas density, and high carrier mobility was obtained. The thin (∼2 nm) crystal bonding interlayer, coupled with the low thermal boundary resistance of only 6.8 m2K/G·W, provides evidence for the low interfacial damage caused by this approach. These results demonstrate its superiority as an attractive method for fabricating high-performance N-polar GaN millimeter-wave devices.

Cooperative dynamic polaronic picture of diamond color centers

Polarons can control carrier mobility and can also be used in the design of quantum devices. Although much effort has been directed into investigating the nature of polarons, observation of defect-related polarons is challenging due to electron-defect scattering. Here we explore the polaronic behavior of nitrogen-vacancy (NV) centers in a diamond crystal using an ultrafast pump-probe technique. A 10-fs optical pulse acts as a source of high electric field exceeding the dielectric breakdown threshold, in turn exerting a force on the NV charge distribution and polar optical phonons. The electronic and phononic responses are enhanced by an order of magnitude for a low density of NV centers, which we attribute to a combination of cooperative polaronic effects and scattering by defects. First-principles calculations support the presence of dipolar Fröhlich interaction via non-zero Born effective charges. Our findings provide insights into the physics of color centers in diamonds.

Exploring eco-friendly novel charge transport materials for enhanced performance of tin based perovskite solar cell

This pioneering simulation study explores the potential of perovskite materials, particularly the non-toxic methyl ammonium tin iodide (MASnI3), in solar cell technology. The investigation focuses on eco-friendly, solution-processed compounds—specifically, WO3 and In2S3 as Electron Transport Layers (ETL) and MoO3 and WSe2 as Hole Transport Layer (HTL)—to develop planar n-i-p MASnI3 perovskite solar cell (PSC) devices. WO3 is chosen for its solution processing and high electron mobility, while In2S3 offers n-type properties, superior carrier mobility, non-toxicity, and thermal durability. MoO3 and WSe2 are selected as HTLs for their efficient charge transport capabilities. Utilizing the solar cell capacitance simulator (SCAPS-1D) software, the study systematically evaluates alternative charge-selective materials, considering various parameters such as thickness (0.1 µm to 1.5 µm for absorber and 0.1 µm to 0.35 µm for CTLs), doping concentration (3.2E10 to 3.2E16 for absorber and E16 to E20 for CTLs), defect density, and energy band offset for MASnI3 PSCs. Four distinct n-i-p device structures are optimized, yielding impressive PCE improvements ranging from 14.63 % to 25.34 %, a significant 3 % enhancement compared to initial results. Notably, the WO3/MASnI3/WSe2 configuration exhibits limitations in electrical performance, while the other optimized structures demonstrate substantial efficiency gains. Further analysis investigates the impact of reflecting coatings (10 % to 90 %), varying contact work functions (5.2–5.8 eV), and temperature (300–400 K) on photovoltaic parameters. Critical factors including energy band offset, recombination current profile, and built-in potential, are meticulously examined, laying the groundwork for advanced PSC implementation. The study culminates in the In2S3/MASnI3/MoO3 device configuration, which achieves a peak efficiency of 25.34 %, showcasing superior thermal stability and an enhanced fill factor, thus propelling all-inorganic PSCs towards practical implementation.

Flexible Perovskite Solar Cells: A Futuristic IoTs Powering Solar Cell Technology, Short Review.

The perovskite solar cells (PSCs) technology translated on flexible substrates is in high demand as an alternative powering solution to the Internet of Things (IOTs). An efficiency of ∼26.1% on rigid and ∼25.09% on flexible substrates has been achieved for the PSCs. Further, it is also reported that F-PSC modules have a surface area of ∼900 cm2, with a PCE of ∼16.43%. This performance is a world record for an F-PSC device more significant than ∼100 cm2. The process optimization, and use of new transport materials, interface, and compositional engineering, as well as passivation, have helped in achieving such kind of performance of F-PSCs. Hence, the review focuses mainly on the progress of F-PSCs and the low-temperature fabrication methods for perovskite films concerning their full coverage, morphological uniformity, and better crystallinity. The transmittance, band gap matching, carrier mobility, and ease of low-temperature processing are the key figures of merit of interface layers. Electrode material's flexible and transparent nature has enhanced the device's mechanical stability. Stability, flexibility, and scalable F-PSC fabrication challenges are also addressed. Finally, an outlook on F-PSC applications for their commercialization based on cost will also be discussed in detail.

Few-layer Bi2O2Se: a promising candidate for high-performance near-room-temperature thermoelectric applications

Advancements in high-temperature thermoelectric (TE) materials have been substantial, yet identifying promising near-room-temperature candidates for efficient power generation from low-grade waste heat or TE cooling applications has become critical but proven exceedingly challenging. Bismuth oxyselenide (Bi2O2Se) emerges as an ideal candidate for near-room-temperature energy harvesting due to its low thermal conductivity, high carrier mobility and remarkable air-stability. In this study, the TE properties of few-layer Bi2O2Se over a wide temperature range (20-380 K) are investigated, where a charge transport mechanism transitioning from polar optical phonon to piezoelectric scattering at 140 K is observed. Moreover, the Seebeck coefficient (S) increases with temperature up to 280 K then stabilizes at∼-200μV K-1through 380 K. Bi2O2Se demonstrates high mobility (450 cm2V-1s-1) within the optimum power factor (PF) window, despite itsT-1.25dependence. The high mobility compensates the minor reduction in carrier densityn2Dhence contributes to maintain a robust electrical conductivity∼3 × 104S m-1. This results in a remarkable PF of 860μW m-1K-2at 280 K without the necessity for gating (Vg= 0 V), reflecting the innate performance of the as-grown material. These results underscore the considerable promise of Bi2O2Se for room temperature TE applications.

Simulation Study for Nb‐Doped MoS2${\rm MoS}_2$ Layer in CZTS‐Based Solar Cells: Assessment of Challenges

AbstractThe unintentional formation of a layer as a reaction product between the copper zinc tin sulfide (CZTS) thin film and the Mo back contact reduces cell efficiency due to high sheet resistance and carrier recombination. To limit the formation of , an intentionally grown p‐type Nb‐doped layer can serve as an effective hole transport layer. This study presents a detailed study and calculations for CZTS/Mo‐based solar cells, providing guidelines for calibration. Optimizing cell efficiency is influenced by various interconnected factors in Nb‐doped . While a high carrier concentration in Nb‐doped is assumed to enhance efficiency, other parameters such as band state, optical absorption, and carrier mobility also play crucial roles and can limit cell performance. This simulation study evaluated the effect of Nb‐doped layers with different carrier concentrations to determine the optimal conditions for this p‐type layer. This work reveals that a very thin layer (13 nm) of Nb‐doped p‐type can achieve a maximum efficiency of 11.34% (with = 1.5 ) and that for an Nb‐doped p‐type 62 nm is 15.82 % (with = 4.03 ).

A stochastic Schrödinger equation and matrix product state approach to carrier transport in organic semiconductors with nonlocal electron-phonon interaction.

Evaluation of the charge transport property of organic semiconductors requires exact quantum dynamics simulation of large systems. We present a numerically nearly exact approach to investigate carrier transport dynamics in organic semiconductors by extending the non-Markovian stochastic Schrödinger equation with complex frequency modes to a forward-backward scheme and by solving it using the matrix product state (MPS) approach. By utilizing the forward-backward formalism for noise generation, the bath correlation function can be effectively treated as a temperature-independent imaginary part, enabling a more accurate decomposition with fewer complex frequency modes. Using this approach, we study the carrier transport and mobility in the one-dimensional Peierls model, where the nonlocal electron-phonon interaction is taken into account. The reliability of this approach was validated by comparing carrier diffusion motion with those obtained from the hierarchical equations of motion method across various parameter regimes of the phonon bath. The efficiency was demonstrated by the modest virtual bond dimensions of MPS and the low scaling of the computational time with the system size.

Molecular Control of the Donor/Acceptor Interface Suppresses Charge Recombination Enabling High-Efficiency Single-Component Organic Solar Cells.

Single-component organic solar cells based on double cable polymers have achieved remarkable performance, with DCPY2 reaching a high efficiency of over 13%. In this study, DCPY2 is further optimized with an efficiency of 13.85%, maintaining a high fill factor (FF) without compromising the short circuit current. Despite its intermixed morphology, DCPY2 shows a reduced recombination rate compared to their binary counterpart (PBDB-T:Y-O6). This slower recombination in DCPY2 is attributed to the reduced wavefunction overlap of delocalized charges, achieved by spatially separating the donor and acceptor units with an alkyl linker, thereby restricting the recombination pathways. Adding 1,8-diiodooctane (DIO) into DCPY2 further reduced the recombination rate by facilitating acceptor aggregation, allowing free charges to become more delocalized. The DIO-assisted aggregation in DCPY2 (5% DIO) is evidenced by an increased pseudo-pure domain size of Y-O6. Fine molecular control at the donor/acceptor interface in the double-cable polymer achieves reduced non-geminate recombination under efficient charge generation, increased mobility, and charge carrier lifetime, thereby achieving superior performance. Nevertheless, the FF is still limited by relatively low mobility compared to the blend, suggesting the potential for further mobility improvement through enhanced higher-dimensional packing of the double-cable material.

Colloidal synthetic environmental design towards high-density twin boundaries and boosted thermoelectric performance in Cu5FeS4 icosahedrons

High-density twin boundaries can significantly influence materials’ functional and mechanical properties. In thermoelectrics, twin engineering is able to manipulate the carrier and phonon transport in semiconductors, leading to improved dimensionless figure of merit (zT). However, obtaining twin boundaries with tunable density and uniform distribution in thermoelectric semiconductors is rather challenging. Here, by precisely controlling the temperature of sulfur precursor, the particle size of synthesized Cu5FeS4 icosahedrons can be decreased to produce higher-density twin boundaries. Accordingly, the optimized average distance between two adjacent twin boundaries matches the mean free path of phonons but is much larger than that of carriers, thereby efficiently lowering the lattice thermal conductivity without affecting the carrier mobility significantly. In combination with the enhanced power factor caused by increased carrier concentration, a maximal zT of 0.95 is achieved at 773 K in a p-type Cu5FeS4 derivative material, which is one of the highest values among those in Earth-abundant, environmentally-friendly thermoelectric sulfides. This work uncovers the crucial role of high-density twin boundaries in decoupling the carrier and phonon transport for improved thermoelectric performance in Cu5FeS4-based materials.

Epitaxial Growth of Ga2O3: A Review.

Beta-phase gallium oxide (β-Ga2O3) is a cutting-edge ultrawide bandgap (UWBG) semiconductor, featuring a bandgap energy of around 4.8 eV and a highly critical electric field strength of about 8 MV/cm. These properties make it highly suitable for next-generation power electronics and deep ultraviolet optoelectronics. Key advantages of β-Ga2O3 include the availability of large-size single-crystal bulk native substrates produced from melt and the precise control of n-type doping during both bulk growth and thin-film epitaxy. A comprehensive understanding of the fundamental growth processes, control parameters, and underlying mechanisms is essential to enable scalable manufacturing of high-performance epitaxial structures. This review highlights recent advancements in the epitaxial growth of β-Ga2O3 through various techniques, including Molecular Beam Epitaxy (MBE), Metal-Organic Chemical Vapor Deposition (MOCVD), Hydride Vapor Phase Epitaxy (HVPE), Mist Chemical Vapor Deposition (Mist CVD), Pulsed Laser Deposition (PLD), and Low-Pressure Chemical Vapor Deposition (LPCVD). This review concentrates on the progress of Ga2O3 growth in achieving high growth rates, low defect densities, excellent crystalline quality, and high carrier mobilities through different approaches. It aims to advance the development of device-grade epitaxial Ga2O3 thin films and serves as a crucial resource for researchers and engineers focused on UWBG semiconductors and the future of power electronics.

Uniaxial Strain Engineering of Anisotropic Phonon in Few‐Layer Violet Phosphorus with High Stretchability for Polarized Sensitive Flexible Photodetector

AbstractThe manifestation of mechanical phenomena in quantum materials at the macroscopic level is intricately linked to pronounced electron‐electron interactions within their lattices, a relationship that becomes especially evident in low‐dimensional materials. Violet phosphorous (VP), a nascent 2D material distinguished by its unique vertically aligned tubular structures, has garnered considerable attention owing to its layer‐dependent electronic bandgap, exceptional carrier mobility, and robust air stability. Herein, a comprehensive exploration of the phonon modes exhibited by few‐layer VP through an integrated experimental‐theoretical approach, focusing on the modulation of their Raman response under the uniaxial strain along a‐axis, b‐axis, and tube direction, respectively, is undertaken. Density functional theory calculations highlight when strain is applied along the a‐ or b‐axis direction, the strain is predominantly mitigated through tube rotational adaptations instead of the change of bond length and bond angle, culminating in a pronounced anisotropic Raman response. Moreover, the strain engineering can effectively optimize the photoelectric response performance of VP, including increase the responsivity ≈2500% and elevate the anisotropic ratio from 2.26 to 3.38. This investigation not only confirms the superior stretchability and impact resistance properties of cross‐structured VP but also establishes the groundwork for exploring the strain‐induced anisotropic optoelectric properties to VP.

Tailoring Polaron Dimensions in Lead-Tin Hybrid Perovskites.

Charge carriers in the soft and polar perovskite lattice form so-called polaron quasiparticles, charge carriers dressed with a lattice deformation. The spatial extent of a polaron is governed by the material's electron-phonon interaction strength, which determines charge carrier effective mass, mobility, and the so-called Mott polaron density, that is, the maximum stable density of charge carriers that a perovskite can support. Despite its significance, controlling polaron dimensions has been challenging. Here, experimental substantial tuning of polaron dimensions is reported by lattice engineering, through Pb/Sn substitution in CH3NH3SnxPb1-xI3. The polaron dimension is deduced from the Mott polaron density, which can be composition-tuned over an order of magnitude, while charge carrier mobility occurs through band transport, and remains substantial across all compositions, ranging from 10s to 100 scm2V s-1 at room temperature. The effective modulation of polaron size can be understood by considering the bond asymmetry after carrier injection as well as the random spatial distribution of Pb/Sn ions. This study underscores the potential for tailoring polaron dimensions, which is crucial for optimizing applications prioritizing either high charge carrier density or high mobility.