Centimeter-Sized Single Crystals of Two-Dimensional Hybrid Iodide Double Perovskite (4,4-Difluoropiperidinium)4AgBiI8 for High-Temperature Ferroelectricity and Efficient X-Ray Detection

Ferroelectricity and X-ray detection property have been recently implemented for the first time in hybrid bromide double perovskites. It sheds a light on achieving photosensitive and ferroelectric multifunctional materials based on 2D lead-free hybrid halide double perovskites. However, the low T_c, small P_s, and relatively low X-ray sensitivity in the reported bromide double perovskites hinder practical applications. Herein, the authors demonstrate a novel 2D lead-free iodide double perovskite (4,4-difluoropiperidinium)₄AgBiI₈ (1) for high-performance X-ray sensitive ferroelectric devices. Centimeter-sized single crystal of 1 is obtained and exhibits an excellent ferroelectricity including a high T_c up to 422 K and a large P_s of 10.5 μC cm⁻². Moreover, due to a large X-ray attenuation and efficient charge carrier mobility (μ)–charge carrier lifetime (τ) product, the crystal 1 also exhibits promising X-ray response with a high sensitivity up to 188 μC·Gy_air⁻¹ cm⁻² and a detection limit below 3.13 μGy_air·s⁻¹. Therefore, this finding is a step further toward practical applications of lead-free halide perovskite in high-performance photoelectronic devices. It will afford a promising platform for exploring novel photosensitive ferroelectric multifunctional materials based on lead-free double perovskites.     

Highly Efficient and Tunable Emission of Lead-Free Manganese Halides toward White Light-Emitting Diode and X-Ray Scintillation Applications

Environmental friendly metal halides have become emerging candidates as energy downconverting emitters for lighting and X-ray imaging applications. Herein, luminescent single crystals of tetramethylammonium manganese chloride (C₄H₁₂NMnCl₃) and tetraethylammonium bromide ((C₈H₂₀N)₂MnBr₄) are synthesized via a facile room-temperature evaporation method. C₄H₁₂NMnCl₃ and (C₈H₂₀N)₂MnBr₄ with octahedrally and tetrahedrally coordinated Mn²⁺ have correspondingly exhibited red and green emission peaking at 635 and 515 nm both originating from ⁴T₁–⁶A₁ transition of Mn²⁺ with high photoluminescence quantum yield (PLQY) of 91.8% and 85.1% benefiting from their specific crystal structures. Thanks to their strong photoexcitation under blue light, high PLQY, tunable emission spectra, good environmental stability, the white light-emitting diode based on blending of C₄H₁₂NMnCl₃ and (C₈H₂₀N)₂MnBr₄ delivers an outstanding luminous efficacy of 96 lm W⁻¹, approaching commercial level, and shows no obvious photoluminescence intensity degradation after 3000 h under operation. In addition, manganese halides also demonstrate interesting characteristics under X-ray excitation, C₄H₁₂NMnCl₃ and (C₈H₂₀N)₂MnBr₄ exhibit steady-state X-ray light yields of 50 500 and 24 400 photons MeV⁻¹, low detectable limits of 36.9 and 24.2 nGy_air s⁻¹, good radiation hardness, and X-ray imaging demonstration with high-resolution of 5 lp mm⁻¹. This work presents a new avenue for luminescent Mn-based metal halides toward multifunctional light-emitting applications.     

Centimeter-Sized Molecular Perovskite Crystal for Efficient X-Ray Detection

Molecular perovskites have demonstrated great potential for ferroelectrics and nonlinear optics; however, their charge transport properties for optoelectronics have rarely been explored. Here, understanding of charge transport behavior of molecular perovskite under X-ray excitation based on centimeter-scale TMCM-CdCl₃ (TMCM⁺, trimethylchloromethyl ammonium) single crystal is demonstrated. The crystal is fabricated from an aqueous solution and exhibits a large bandgap of 5.51 eV, with the valence band maximum mainly dominated by the Cl-p/Cd-d states and the conduction band minimum primarily by Cd-s/Cl-p states. Charge mobility exceeding 40 cm² V⁻¹ s⁻¹ and mobility–lifetime (µτ) product on the order of 10⁻⁴ cm² V⁻¹ for the crystal are observed. These excellent optoelectronic properties translate to an efficient photoresponse under X-ray excitation, with the sensitivity reaching 128.9 ± 4.64 µC Gy_air⁻¹ cm⁻² [fivefold higher than that of the commercialized amorphous selenium (α-Se)] and a low detection limit of 1.06 μC Gy_air⁻¹ s⁻¹ (10 V bias). This work pioneers a superior metal-based molecular perovskite single-crystal based paradigm for optoelectronic investigation, which may lead to the discovery of a new generation of X-ray detection and imaging materials.     

Ceramic Wafer Scintillation Screen by Utilizing Near-Unity Blue-Emitting Lead-Free Metal Halide (C8H20N)2Cu2Br4

Scintillators with high light yield, low detection limit, large X-ray attenuation efficiency as well as stable and nontoxic compositions are of great importance for radiation detection applications. Here, 0D (C₈H₂₀N)₂Cu₂Br₄ single crystals are obtained and show blue emission peaking at 468 nm with a near-unity photoluminescence quantum yield of 99.7%, a large Stokes shift of 148 nm (i.e., negligible self-absorption), and a good environmental stability along with strong X-ray absorption capability. Moreover, a high light yield of up to ≈ 91 300 photons/MeV and a low detection limit of 52.1 nGy_air s⁻¹ are realized, which is more than one hundred times lower than the dose rate of 5.5 µGy_air s⁻¹ required for X-ray medical diagnostics. (C₈H₂₀N)₂Cu₂Br₄ ceramic wafer scintillation screen is fabricated by a cold pressing sintering process, and the clear contrast images of opaque metal box and electronic component with a spatial resolution of 9.54 lp mm⁻¹ are realized. This study not only designs a new lead-free metal halide scintillator, but also develops a universal strategy for the preparation of large-sized scintillator screen in nondestructive X-ray imaging.     

Low-Cost and Large-Area Hybrid X-Ray Detectors Combining Direct Perovskite Semiconductor and Indirect Scintillator

Both semiconductors and scintillators have their own advantages in direct and indirect X-ray detection, respectively. However, they are also limited by their intrinsic properties and detection mechanisms. Here, a low-cost and large-area flat X-ray detector is reported by combining a cesium silver bismuth bromide (Cs₂AgBiBr₆) perovskite semiconductor with a ethylenebis-triphenylphosphonium manganese (II) bromide ((C₃₈H₃₄P₂)MnBr₄) scintillator through fast tableting processes. Cs₂AgBiBr₆ and (C₃₈H₃₄P₂)MnBr₄ can attenuate the X-ray photons to induce charge carriers that are collected through the continuous Cs₂AgBiBr₆ grains. (C₃₈H₃₄P₂)MnBr₄ blocks the Cs₂AgBiBr₆ ions migration paths at the grain boundaries to reduce the device dark current/noise and improves the working stability. Most charges generated by (C₃₈H₃₄P₂)MnBr₄ are transferred to the adjacent Cs₂AgBiBr₆, and recombined charges radiate light through scintillation, which will be further absorbed by the surrounding Cs₂AgBiBr₆ perovskite, and further induce collectable charges for indirect X-ray detection, avoiding the unwanted light scattering, self-absorption, or afterglow effects of scintillators. The hybrid X-ray detector displays a high sensitivity of 114 µC Gy_air⁻¹ cm⁻² to 120 keV_p hard X-rays with a lowest detectable dose rate of 0.2 μGy_air s⁻¹, showing 75 times lower detection limit compared to (C₃₈H₃₄P₂)MnBr₄ scintillator, which provides a new path for X-ray flat-panel design.     

Sintered Polycrystalline BiVO4 Pellet for Stable X-Ray Detector with Low Detection Limit

Semiconductors based on Bi element show large attenuation coefficients to X-ray photons and have been recognized as candidates for X-ray detectors. However, the application of stable Bi-based oxide materials to X-ray detectors has been rarely investigated. In this research, the X-ray response of a BiVO₄ pellet has been studied. It has been found that the BiVO₄ pellet has a large resistivity of 1.3 × 10¹² Ω cm, negligible current drift of 6.18 × 10⁻⁸ nA cm⁻¹ s⁻¹ V⁻¹ under electrical bias and mobility lifetime product, µτ, of 1.75 × 10⁻⁴ cm² V⁻¹, which renders the pellet with an X-ray sensitivity of 241.3 µC Gy_air⁻¹ cm⁻² and a detection limit of 62 nGy_air s⁻¹ under 40 KVp X-ray illumination and 40 V bias voltage. The BiVO₄ pellet also shows operational stability under steady X-ray illumination with total dose of 2.01 Gy_air, equal to the dose of 20 000 medical chest X-ray inspections. This research reveals the potential application of BiVO₄ in X-ray detection devices and inspires further research in this area.     

Suppression of Ionic and Electronic Conductivity by Multilayer Heterojunctions Passivation Toward Sensitive and Stable Perovskite X-Ray Detectors

Organic-inorganic hybrid perovskites are promising candidates for direct X-ray detection and imaging. The relatively high dark current in perovskite single crystals (SCs) is a major limiting factor hindering the pursuit of performance and stability enhancement. In this study, the contribution of dark current is disentangled from electronic (σ_e) and ionic conductivity (σ_i) and shows that the high σ_i dominates the dark current of MAPbBr₃ SCs. A multilayer heterojunctions passivation strategy is developed that suppresses not only the σ_i by two orders of magnitude but also σ_e by a factor of 1.6. The multilayer heterojunctions passivate the halide vacancy defects and increase the electron and hole injection barrier by inducing surface p-type doping of MAPbBr₃. This enables the MAPbBr₃ SC X-ray detectors to obtain a high sensitivity of 19 370 µC Gy_air⁻¹ cm⁻² under a high electric field of 100 V cm⁻¹, a record high sensitivity for bromine self-powered devices, and a low detection limit of 42.3 nGy_air s⁻¹. The unencapsulated detectors demonstrate a stable baseline after storage for 210 days and outstanding operational stability upon irradiation with an accumulated dose of up to 1944 mGy_air.     

Lone-pair Electrons Enhancement Effect: SnTe3O8 Hard X-ray Detection with Stable High-temperature Sensitivity and Ultralow Detection Limit

Sensitivity and detection limit of X-ray detectors are crucial for security checks, medical diagnoses, and industrial inspections. In this study, it is reported that introducing some cations containing lone-pair electrons is beneficial for enhancing the Compton scattering effect and thus improving X-ray detection performance. As an example, SnTe₃O₈ is selected and grown as a novel high-temperature X-ray detection crystal. Because of the high resistivity of 2 × 10¹⁴ Ω cm and high mobility lifetime product of 3.22 × 10⁻⁴ cm² V⁻¹, SnTe₃O₈ X-ray detector exhibits a high sensitivity of 436 µC Gy_air⁻¹ cm⁻² under 120 keV hard X-ray, a low dark current drift of 2.44 × 10⁻⁹ nA cm⁻¹ s⁻¹ V⁻¹ and a record low detection limit of 8.19 nGy_air s⁻¹ among all oxide X-ray detectors. Furthermore, the high-temperature sensitivity of SnTe₃O₈ X-ray detector is enhanced to 617 µC Gy_air⁻¹ cm⁻² at 175 °C, which is ≈31 times larger than that of the commercial α-Se. The high thermal stability and stable high-temperature sensitivity of SnTe₃O₈ single crystal X-ray detectors have potential applications in high-temperature environments. The results not only provide an excellent high-temperature X-ray detection crystal but also propose an effective method to explore X-ray detector materials with excellent performances.     

Giant Emission Enhancement from Hybrid Manganese Bromide Via Pressure-Induced Band-Edge Carrier Reconfiguration

Pressure-induced emission enhancement (PIEE) is a novel phenomenon in contrast to conventional pressure-induced emission quenching, and has attracted considerable attention owing to the potential application of materials with this effect as optical pressure-sensing devices. The urgent need and significant significance lie in the design and exploration of systems that possess high-efficiency PIEE. Here, a large PIEE in a novel zero-dimensional (0D) hybrid manganese bromide is realized, (BPPH)₂MnBr₄·1.5CH₃CN [BPPH⁺ = bis(triphenylphosphine)iminium]. The experimental and theoretical results demonstrate that such emission enhancement is primarily attributed to the pressure-induced reconfiguration of electronic band alignment and resultant redistribution of band-edge excitons. Under compression, the electronic bandgap of (MnBr₄)²⁻ experiences a more rapid reduction compared to that of the organic cations. Consequently, this leads to the gradual closure of the charge transfer pathway from (MnBr₄)²⁻ to BPPH⁺. This progression results in a higher retention of excitons on (MnBr₄)²⁻, amplifying the efficiency of Mn²⁺ d–d transitions, and leading to a substantial enhancement in emission. This study not only offers fresh insights into the behavior of carrier dynamics induced by pressure in hybrid manganese halides but also presents a promising avenue for the advancement of PIEE systems.     

Stable and Bright Pyridine Manganese Halides for Efficient White Light-Emitting Diodes

Highly efficient lead halide perovskites with tunable emission performance have become new candidate materials for light-emitting devices and displays; however, the toxicity of lead and instability of halide perovskites greatly limits their application. Herein, rapid and large-scale synthesis of highly emissive organic–inorganic manganese halide perovskites, (C₅H₆N)₂MnBr₄ and C₅H₆NMnCl₃, are presented by a one-pot solution-based method, of which (C₅H₆N)₂MnBr₄ displays a high absolute photoluminescence quantum yield (95%) in the solid-state. The developed (C₅H₆N)₂MnBr₄ perovskite noticeably exhibits high stability. Therefore both as-synthesized green and red emissive manganese-based phosphors with superior optical properties are used to fabricate blue light pumped white light-emitting diodes (WLEDs), displaying excellent quality white light with a high color rendering index value of 91 and a correlated color temperature of 5331 K. This study not only presents the robust large-scale production synthetic approach for organic–inorganic manganese halide perovskites, but also facilitates the development of high-performance phosphors for future lighting and display technologies.     

2D-Layered Manganese Perovskite with High Mobility

2D perovskite is an organic–inorganic hybrid material with good photoelectric properties, generally prepared by using organic groups as isolation molecules. In this study, using manganese chloride and potassium halide as raw materials, all-inorganic 2D lead-free perovskites are prepared by the Bridgeman melting and cooling method. Different from the 2D perovskites synthesized by organic spacer molecules, the prepared all-inorganic 2D perovskites have smaller layer spacings and good crystallization performance due to the use of potassium halide as spacer molecules. They are direct bandgap semiconductors and their energy bandgaps are tuned by the different types of potassium halides. High degree orientation crystal thin films with (001) lattice plane parallel to silicon wafer substrate are prepared by double-source evaporation. The physical morphology of the films is characterized by grazing angle X-ray diffraction, transmission electron microscopy, and electron diffraction. The field effect transistors prepared from these 2D films show excellent electronic characteristics. The mobility of the optimized device is ≈24 cm² v⁻¹ s⁻¹ and the on/off ratio reaches 10⁵. This study reveals the potential of lead-free manganese 2D perovskite as a high-performance perovskite field effect transistor.     

Ultra-Low Dark Current Organic–Inorganic Hybrid X-Ray Detectors

Organic-inorganic hybrid semiconductors are an emerging class of materials for direct conversion X-ray detection due to attractive characteristics such as high sensitivity and the potential to form conformal detectors. However, existing hybrid semiconductor X-ray detectors display dark currents that are 1000–10 000× higher than industrially relevant values of 1–10 pA mm⁻². Herein, ultra-low dark currents of <10 pA mm⁻², under electric fields as high as ≈4 V µm⁻¹, for hybrid X-ray detectors consisting of bismuth oxide nanoparticles (for enhanced X-ray attenuation) incorporated into an organic bulk heterojunction consisting of p-type Poly(3-hexylthiophene-2,5-diyl) (P3HT) and n-type [6,6]-Phenyl C71 butyric acid methyl ester (PC₇₀BM) are reported. Such ultra-low dark currents are realized through the enrichment of the hole selective p-type organic semiconductor near the anode contact. The resulting detectors demonstrate broadband X-ray response including an exceptionally high sensitivity of ≈1.5 mC Gy⁻¹ cm⁻² and <6% variation in angular dependence response under 6 MV hard X-rays. The above characteristics in combination with excellent dose linearity, dose rate linearity, and reproducibility over a broad energy range enable these detectors to be developed for medical and industrial applications.     

Solvent-Free Synthesis of Inorganic Rubidium Copper Halides for Efficient Wireless Light Communication and X-Ray Imaging

Lead-free metal halides have recently received sustained attention because of their nontoxicity, low-cost, as well as excellent stability and optoelectronic properties. However, most of the reported lead-free metal halides are synthesized via slow solution-processing at high temperature in toxic solvents, which may impede their commercial applications. Here, a solvent-free strategy is proposed to synthesize inorganic rubidium copper halides (Rb₂CuX₃, X = Cl, Br) at room temperature, which exhibit efficient violet emission dominated by a self-trapped excitons (STEs) mechanism and attractive stabilities against ultraviolet illumination and heating. Thus, Rb₂CuX₃ powders are employed as emitters and scintillators applied in wireless light communication and X-ray imaging technologies. Under orthogonal frequency division multiplexing modulation, emitters demonstrate a broad −3 dB bandwidth of 26.3 MHz and a high received data rate of 205.1 Mbps. Additionally, flexible scintillation films based on as-prepared powders are fabricated and show outstanding X-ray scintillation properties, including a high spatial resolution of 18.1 lp mm⁻¹ and a low detection limit of 104 nGy_air s⁻¹, as well as promising imaging performance for irregular objects. These results suggest large-scale production of nontoxic Rb₂CuX₃ and their potential commercialization in fields of high-speed light communication and X-ray radiography.     

Inch-Size Single Crystals of Lead-Free Chiral Perovskites with Bulk Photovoltaic Effect for Stable Self-Driven X-Ray Detection

Lead halide perovskites have made great advance in direct X-ray detection, however the presence of toxic lead and the requirement of high working voltages severely limit their applicability and operational stability. Thus, exploring “green” lead-free hybrid perovskites capable of detecting X-rays at zero bias is crucial but remains toughly challenging. Here, utilizing chiral R/S-1-phenylpropylamine (R/S-PPA) cations, a pair of 0D chiral-polar perovskites, (R/S-PPA)₂BiI₅ ( 1 R / 1 S ) are constructed. Their intrinsic spontaneous electric polarization induces a large bulk photovoltage of 0.63 V, which acts as a driving force to separate and transport photogenerated carriers, thus endowing them with the capability of self-driven detection. Consequently, self-driven X-ray detectors with a low detection limit of 270 nGy s⁻¹ are successfully constructed based on high-quality, inch-sized single crystals of 1 R . Notably, they show suppressed baseline drift under the self-driven mode, exhibiting superior operational stability. This study realizes self-driven X-ray detection in a single-phase lead-free hybrid perovskite by exploiting the intrinsic bulk photovoltaic effect, which sheds light on future explorations of lead-free hybrid perovskites toward “green” self-driven radiation detectors with high performance.     

Optimization of N2/Ar gas flow ratio for the realization of nitrogen-doped p-type ZnCdO thin films synthesized by RF magnetron sputtering

Nitrogen doped ZnCdO films [ZCO:N] have been grown on quartz substrates by radio frequency (RF) reactive magnetron sputtering technique, and the effect of the ratio of nitrogen to argon gas flow [N₂:Ar] on their electrical, microstructure and optical properties were investigated by Hall effect, energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscope (TEM), optical absorbance and photoluminescence (PL) measurements. The results indicate that all the ZCO:N films are of hexagonal wurtzite structure with highly (002) preferential orientation. As the N₂:Ar increases from 0:1 to 4:1, the absorption edge for the samples exhibits blue shift. Hall effect measurement results indicate that the N₂:Ar exerts an immense influence on the p-type conduction conversion for ZCO:N film. It is found that ZCO:N film deposited at the N₂:Ar of 1:2 shows the optimal p-type behavior, which has a carrier concentration of 1.10×10¹⁷ cm⁻³, a mobility of 3.28 cm²V⁻¹s⁻¹ and a resistivity of 17.3 Ω cm. Compared with the other samples, ZCO:N film fabricated at the relatively lower N₂:Ar possesses the superior crystal quality, luminescent and electrical properties. Additionally, a possible mechanism of p-type conduction for ZCO:N film was discussed in this work.     

Effects of gate dielectric surface modification on phototransistors with polymer-blended benzothieno[2,3-b]benzothiophene semiconductor thin films

In the present work, we investigated effects of the dielectric/semiconductor interface modification on the photoelectrical properties of phototransistors comprising a UV responsive semiconductor blend 2,7-dipentyl-[1]benzothieno[2,3-b][1]benzothiophene (C5-BTBT) and a linear unsaturated polyester (L-upe). Using various self-assembly monolayers with different end-groups at the dielectric/semiconductor interface we modulated the drain photocurrent and response times under the UV light illumination of phototransistors. Treatment of the SiO₂ dielectric surface with organosilanes led to the variation of the max mobility in the dark 0.10–0.18 cm² V⁻¹ s⁻¹ and under UV light 0.08–0.50 cm² V⁻¹ s⁻¹. Interestingly, detailed crystal structure analysis using 2D X-ray diffraction and photoelectrical characterization revealed that mobility in the dark predominantly depends on the alignment of C5-BTBT crystallites at the interface. Under UV light, the mobility increased with the electron withdrawing/donating nature of the SAM end-functional group. Additionally, chemical modification of the SiO₂ dielectric surface increased photocurrent relaxation/decay times upon UV light removal while retaining fast response times when exposed to UV light, which enhanced memory properties of fabricated phototransistors (fast UV response = writing and long relaxation = long data storage).     

X-ray Sensitive hybrid organic photodetectors with embedded CsPbBr3 perovskite quantum dots

X-ray detection is an important technology for medical diagnosis as well as industrial and security inspections. While today's commercial X-ray detectors are bulky, photodetectors based on organic semiconductors have attracted increasing attention owing to their low temperature processing capabilities, flexibility and low cost. Nonetheless, the low X-ray attenuation coefficient of organic semiconductors still hinders their practical application. Herein, a new organic-inorganic hybrid strategy is proposed to improve the X-ray sensitivity of organic photodetectors (OPDs). A solution-processed X-ray sensitive hybrid OPD is fabricated by embedding CsPbBr₃ quantum dots (QDs) into a P3HT:PC₆₁BM bulk heterojunction photodiode. The QDs, acting as embedded scintillators in the organic active layer, maintain a high radioluminescence. The proposed hybrid structure enables indirect X-ray detection in a comprehensive manner. These hybrid photodetectors exhibit suppressed dark current densities in the range of tens of picoamperes per square centimeters for different weight ratios of blended QDs. The best OPD achieves a sensitivity of 229.6 e nGy⁻¹ mm⁻² (3.67 μC Gy⁻¹ cm⁻²) and a dark current of 23.3 pA cm⁻² at a low operating voltage (−3 V) for 20–80 kV “soft” X-rays, thus representing great potential for the development of next generation low cost, portable, and highly sensitive X-ray detectors.     

Metal Halide Scintillators with Fast and Self-Absorption-Free Defect-Bound Excitonic Radioluminescence for Dynamic X-Ray Imaging

Scintillators for radiation detection are of great significance in medical imaging, security, and nondestructive inspection. The current challenge for scintillators is to simultaneously achieve high scintillation light yield, fast radioluminescence, simple film fabrication, large X-ray attenuation efficiency as well as stable and nontoxic compositions; no previous scintillators fulfill all the above requirements. Here, metal halide Rb₂AgBr₃, possessing defect-bound excitonic radioluminescence, is shown as efficient and fast scintillators. This nontoxic and stable scintillator emits from excitons bound to neutral bromine vacancies, enjoying an efficient and spin-allowed fast emission with minimized self-absorption. Rb₂AgBr₃ thus has a high light yield (25 600 photons MeV⁻¹), fast scintillation decay time (5.31 ns), and a record value of light yield versus decay time (4821 photons MeV⁻¹ ns⁻¹). The close-space sublimation method is developed for fast and scalable fabrication of oriented Rb₂AgBr₃ films. The scintillator film is further integrated with commercial flat-panel imagers, and the spatial resolution reaches 10.2 line pairs per millimeter at the modulation transfer function of 0.2, doubling the resolution of conventional CsI:Tl flat-panel detectors. The dynamic X-ray imaging and its use to real-time monitoring of bone movement without ghosting effect is also demonstrated.     

Flexible and Air-Stable Near-Infrared Sensors Based on Solution-Processed Inorganic–Organic Hybrid Phototransistors

Flexible and air-stable phototransistors are highly demanded for wearable near-infrared (NIR) image sensors. However, advanced NIR sensors via low-cost, solution-based processes remained a challenge. Herein, high-performance inorganic–organic hybrid phototransistors are achieved based on solution processed n-type metal oxide/polymer semiconductor heterostructures of In₂O₃/poly{5,5′-bis[3,5-bis(thienyl)phenyl]-2,2′-bithiophene-3-ethylesterthiophene]} (PTPBT-ET). The In₂O₃/PTPBT-ET hybrid phototransistor combines the advantages of both fast electron transport in In₂O₃ and high photoresponse in PTPBT-ET, showing high saturation mobility of 7.1 cm² V⁻¹ s⁻¹ and large current on/off ratio of >10⁷. As a result, the phototransistor exhibits high performance towards NIR light sensing with a responsivity of 200 A W⁻¹, a specific detectivity of 1.2 × 10¹³ Jones, and fast photoresponse with rise/fall time of 5/120 ms. Remarkably, the hybrid phototransistor, without any passivation, demonstrates excellent electrical stability without performance degradation even after 160 days in air. A 10 × 10 phototransistor array is also enabled by virtue of the high device uniformity. Lastly, flexible In₂O₃/PTPBT-ET phototransistor on polyimide substrate is attained, exhibiting outstanding mechanical flexibility up to 1000 bending/releasing cycles at a bending radius of 5 mm. These achievements pave the way for constructing air-stable hybrid phototransistors for flexible NIR image sensor applications.     

High-Performance Photodetector and Angular-Dependent Random Lasing from Long-Chain Organic Diammonium Sandwiched 2D Hybrid Perovskite Non-Linear Optical Single Crystal

3D organic-inorganic metal halide perovskites are excellent materials for optoelectronic applications due to their exceptional properties, solution processability, and cost-effectiveness. However, the lack of environmental stability highly restricts them from practical applications. Herein, a stable centimeter-long 2D hybrid perovskite (N-MPDA)[PbBr₄] single crystal using divalent N1-methylpropane-1,3-diammonium (N-MPDA) cation as an organic spacer, is reported. The as-grown single crystal exhibits stable optoelectronic performance, low threshold random lasing, and multi-photon luminescence/multi-harmonic generation. A photoconductive device fabricated using (N-MPDA)[PbBr₄] single crystal exhibits an excellent photoresponsivity (≈124 AW⁻¹ at 405 nm) that is ≈4 orders of magnitudes higher than that of monovalent organic spacer-assisted 2D perovskites, such as (BA)₂PbBr₄ and (PEA)₂PbBr₄, and large specific detectivity (≈10¹² Jones). As an optical gain media, the (N-MPDA)[PbBr₄] single crystal exhibits a low threshold random lasing (≈6.5 µJ cm⁻²) with angular dependent narrow linewidth (≈0.1 nm) and high-quality factor (Q ≈ 2673). Based on these results, the outstanding optoelectronic merits of (N-MPDA)[PbBr₄] single crystal will offer a high-performance device and act as a dynamic material to construct stable future electronics and optoelectronic-based applications.