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The importance of bacteria detection lies in its role in enabling early intervention, disease prevention, environmental protection, and effective treatment strategies. Advancements in technology continually enhance the speed, accuracy, and sensitivity of detection methods, aiding in addressing these critical issues. This study first reports the fabrication of an inverter constructed using crosslinked-poly(4-vinylphenol) (C-PVP) as the dielectric layer and an organic complementary metal-oxide semiconductor (O-CMOS) based on pentacene and N,N′-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (PTCDI-C13) as a diagnostic biosensor to rapidly detect bacterial concentration. Bacteria including Escherichia coli O157, Staphylococcus aureus ATCC25922, and Enterococcus faecalis SH-1051210 were analysed on the inverters at an ultra-low operating voltage of 2 V. The high density of negative charge on bacteria surfaces strongly modulates the accumulated negative carriers within the inverter channel, resulting in a shift of the switching voltage. The inverter-based bacteria sensor exhibits a linear-like response to bacteria concentrations ranging from 102 to 108 CFU/mL, with a sensitivity above 60%. Compared to other bacterial detectors, the advantage of using an inverter lies in its ability to directly read the switching voltage without requiring an external computing device. This facilitates rapid and accurate bacterial concentration measurement, offering significant ease of use and potential for mass production. [ABSTRACT FROM AUTHOR]

Unveiled as a unique feature of polymer ferroelectric crystals, oriented coalescence within monolayers of poly(vinylidenefluoride‐co‐trifluoroethylene)(PVDF‐TrFE) ferroelectric crystals has been found regulable upon monolayer roughness, which is accompanied by the adjustment of piezoelectric responses, and thus phase polarity. Simply with the deposition of poly(3‐hexylthiophene (P3HT)‐wrapped molybdenum disulfide (MoS2) sheets, piezoelectric responses of polymer ferroelectric crystals are surprisingly enhanced further. Also dependent on the degrees of phase polarity, the binding energy of P3HT excitons declines to a level comparable to that of inorganic excitons, together with the alteration of work functions. These results suggest mutual polarization between ferroelectric lamellar crystals and originally nonpolar P3HT‐wrapped MoS2 sheets as a result of dipole‐induced dipole phase interactions. As the Fermi levels and driving forces of interfacial electron transition are also adjustable upon involved phase interactions, P3HT‐wrapped MoS2 sheets can photocatalyze hydrogen evolution with an average production rate reaching 4.474 mmol g−1 h−1, which is 1.6 times higher than the results without the aid of phase interactions. Accordingly, amplifying phase interactions has been elucidated feasible, and able to serve as a promising approach to generally promote photocatalytic reactions. [ABSTRACT FROM AUTHOR]

In this study, a high-K material, aluminum oxide (AlOx), as the dielectric of organic field-effect transistors (OFETs) was used to reduce the threshold and operating voltages, while focusing on achieving high-electrical-stability OFETs and retention in OFET-based memory devices. To achieve this, we modified the gate dielectric of OFETs using polyimide (PI) with different solid contents to tune the properties and reduce the trap state density of the gate dielectric, leading to controllable stability in the N, N'-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (PTCDI-C13)-based OFETs. Thus, gate field-induced stress can be compensated for by the carriers accumulated due to the dipole field created by electric dipoles within the PI layer, thereby improving the OFET's performance and stability. Moreover, if the OFET is modified by PI with different solid contents, it can operate more stably under fixed gate bias stress over time than the device with AlOx as the dielectric layer only can. Furthermore, the OFET-based memory devices with PI film showed good memory retention and durability. In summary, we successfully fabricated a low-voltage operating and stable OFET and an organic memory device in which the memory window has potential for industrial production. [ABSTRACT FROM AUTHOR]

We investigated the structural properties of organic–inorganic lead halide perovskite microwires through joint experimental and theoretical Raman spectroscopy. High‐quality methyl ammonium lead iodide (MAPBI3, MA = CH3NH3+) microwires with tetragonal phases and explicit crystalline orientation were prepared. Raman spectroscopy was used in studying the as‐prepared microwires and determining not only the crystal quality but also crystalline orientation of MAPBI3 with the aid of normal mode calculations. High‐quality structural features were verified by well‐resolved Raman peaks related to the inorganic cage (IPbI stretching and bending modes below 100 cm−1), organic MA cation motions (libration ~150–200 cm−1 and torsional ~200–250 cm−1), a coupled mode of cage and MA cation liberation (~105–110 cm−1), and the almost undetectable degraded signal at 95 cm−1. In micro‐Raman mapping, an intensity ratio of 105 and 95 cm−1 was used for the direct imaging of crystal quality along the microwire. The characterization of the crystalline orientation of MAPBI3 microwires posed a challenge, which can be addressed by using polarized Raman technique with normal mode analysis. We believe that the proposed method can be extended to other organic–inorganic lead halide perovskites with different structures, such as polycrystalline films and single crystals. [ABSTRACT FROM AUTHOR]

In this study, the multimode photoresponse (PR) features of low-voltage-driven pentacene-based organic phototransistors (OPTs) are reported by utilizing poly(4-vinylphenol) (PVP)-based gate dielectrics containing spiropyran-merocyanine (SP-MC) photochromic materials. In general, pentacene-based OPTs respond to visible light but cannot sense ultraviolet (UV) light. Incorporating SP-MC molecules provides pentacene-based OPTs with the functions of not only sensing UV light but also exhibiting different response modes to UV and visible light and thus can be used to distinguish UV and visible light sources. When the as-prepared OPTs are exposed to UV light, they can simulate the characteristics of typical paired-pulse facilitation and long-term potentiation properties as observed in photonic synaptic devices. The corresponding UV photovoltaic effects in the as-prepared OPTs are investigated in joint experimental measurements and theoretical calculations. We found large amounts of MC molecules in the prepared PVP:SP blend-based dielectrics in the dark, showing that pentacene-based OPTs have unique PR features in contrast to gate dielectrics that contained only SP. MC is an isoform of SP that is typically triggered by irradiation with UV light. Theoretical calculation results indicate that the MC form has large dipole moment features during photoexcitation and several charge transfer states exist, leading to easy separation of photogenerated charges. By contrast, SP does not have the above characteristics. Accordingly, a unique PR mechanism between UV and visible light of the present OPTs is drawn. Several distinct PR types of the as-prepared pentacene-based OPTs expand the functionality of the devices, enhancing their potential for further diverse applications. [ABSTRACT FROM AUTHOR]

Low-voltage organic memory transistors (LOMTs) as data storage units are crucial for the advancements of future flexible electronics. However, charge storage mechanism remains a great challenge. In this work, we used poly(2,5-bis(3-tetradecylthiophen-2-yl)thieno(3,2-b)thiophene) (PBTTT-C14) as the active layer and incorporated poly(methyl methacrylate) (PMMA) with the PBTTT-C14 through a simple blending process to fabricate LOMTs with porous structure. The function of the porous structure was to improve the carrier traps, which can effectively capture the holes at the charge trapping regions during the programming process. A maximum threshold voltage shift of 1.01 V was achieved when the weight ratio of PBTTT-C14 and PMMA is 7:3, and the LOMTs were operated under the programming process of âˆ'4 V/1 s. Impedance-admittance analyses were used to investigate the interfacial trap density of charge trapping regions, which is a supporter of the programming capability of LOMTs. An ultrathin dioctyl perylene tetracarboxylic diimide film was deposited on the active layer with porous structure in LOMTs. This film can increase the carriers’ erasing capability. A wide memory window of 1.64 V was obtained in LOMTs when the devices are operated under the erasing process of bias pulse of 3 V/1 s with the assistance of 2.5 mW cmâˆ'2 light irradiation. This study facilitates the development of high-performance LOMT device in fresh-type memory. [ABSTRACT FROM AUTHOR]

The interfaces between dielectric films and organic semiconductors are used as carrier traps in organic memory devices. The trapping and release capabilities of carriers must be controlled in memory devices. However, the memory windows of these devices are limited by the carriers' erasing capability. In this work, a series of nano-pentacene films were inserted into n-type dioctyl perylene tetracarboxylic diimide (PTCDI-C13) semiconductor layers near the interface of a dielectric film and an organic semiconductor to form field-effect type memory devices with nano-p–n junctions. The presence of nano-p–n junctions near the interface increased minorities (i.e., holes), which could effectively erase accumulated electrons at the interface during erasing. We achieved a maximum memory window of 48.9 V when a 5 nm-thick pentacene film was inserted into the PTCDI-C13 layer and the memory device was operated under a programming process of 90 V and an erasing process of −90 V. Kelvin probe force and noncontact atomic force microscopy were used to investigate the monolayer growth of pentacene and PTCDI-C13 as well as their interface properties. Although the thickness of the pentacene film reached 10 nm, an incomplete layer was formed. This layer supported minorities during erasing and transmitted electrons during programming. A wide memory window was achieved by the nano-p–n heterojunction field-effect memory transistor. This high-performance organic memory device has potential applications in fresh-type memory devices. [ABSTRACT FROM AUTHOR]

The shift of the open-circuit voltage (Voc) of flexible organic solar cells (OSCs) under bending conditions was investigated by fabricating bi-layer heterojunction and polymer-based OSCs on flexible polyethylene terephthalate (PET) substrates. To realize the performance variations of flexible solar cells characterized by important parameters, Voc was measured when the substrate was bent under various curvatures. The Voc was increased and decreased by using tensile and compressive stresses, respectively. The ratio of increase for Voc is larger than the ratio of reduction, thus indicating that the intermolecular distance of an organic semiconductor is difficult to change because of the strong electrostatic repulsive force. A quantitative analysis of energy levels by the photoluminescence spectrum, UV-visible absorption spectrum, and quantum chemical calculation at various bending states was used to explain the Voc as a function of bending curvature. The peak shifts of UV-visible absorption and photoluminescence spectra provide direct evidence of the variation in energy levels when devices are bent, which causes Voc shifts. For bent organic semiconductor films, the bending curvature-dependent intermolecular distance was studied by Raman spectroscopy by analyzing the intermolecular coupling energy. This study shows that the change of Voc cannot be neglected in the application of flexible OSCs on a flexible loading circuit. [ABSTRACT FROM AUTHOR]

This study presents an approach to design hybrid dielectrics with ultrahigh capacitance density at extremely low supply voltages that behave like supercapacitors and are thus energy efficient. Hybrid dielectrics are fabricated from polymer/metal-oxide bilayer films with real-time and effective internal voltage generated by chemically interlocking interfacial species at the charged state. The designed dielectrics are named charged-state dipole-enhanced (CSDE) dielectrics. We demonstrate their potential use in ultralow voltage driving organic field-effect transistors (FETs) characterized by the high performance and great stability. Using the CSDE dielectrics, organic FETs with a pentacene active layer can deliver adequate performance and excellent operational stability at ultralow operating voltage in air. The linear field-effect mobility of pentacene-based FETs can be as high as 1.5 cm2 V−1 s−1 at only 0.1 V. After long-term storage and continuous operation in air, the FETs still exhibited outstanding electrical performance. Several advantageous features of the designed CSDE dielectrics are presented, thereby providing a glimpse into the future of energy-efficient electronics. [ABSTRACT FROM AUTHOR]

We report on the ambipolar charge transport modulation of organic semiconductors (OSCs) in field-effect transistors (FETs) based on joint experimental and theoretical studies. We investigated pentacene, one of the most widely studied OSCs, as an example to achieve efficient and balanced ambipolar FETs (i.e., electron mobility is as fast as hole mobility) via fine control of the interfacial properties of the active channel. Through elimination of the interfacial tension of the active channel, ultrahigh performance pentacene-based ambipolar FETs were achieved, with electron and hole mobilities both near 3.0 cm2 V−1 s−1 in the same channel. Theoretical investigation of the pentacene molecule showed that the electron density is mainly located on the terminal ends but the hole density is on the centered three aromatic rings, a finding that provides insight into the difficulty of observing high electron mobility levels compared with hole mobility in FETs. Analysis of theoretical vibrational reorganization energy supports that electron transport between pentacene molecules suffers from more serious interfacial effects than hole transport. With the help of theoretical calculations, Raman spectroscopy can be used to characterize pentacene films at an early stage of growth at the nanometer scale to assess the ambipolar transport potential in FETs. The results demonstrate an excellent connection between ambipolar characteristics in actual organic FETs and microscopic molecular-level properties, thereby advancing the design and synthesis of new OSCs for electronic and photonic applications. [ABSTRACT FROM AUTHOR]

Control of the operating voltage in organic thin-film transistor (OTFT) based photosensors is a very important issue, which can effectively enhance photosensitivity by reducing the contribution of the field-effect current to the output current under darkness. In this study, we show a highly sensitive flexible organic photosensor, which is made by the use of cross-linked poly(4-vinylphenol) as a polymer dielectric layer and N,N′-ditridecyl-3,4,9,10-perylenetetracarboxylic diimide (PTCDI-C13H27) as an n-type active layer on a transparent polyethersulfone (PES) substrate, by tuning both source–drain and source–gate voltages to around the threshold voltage (Vt = 3.0 V). Interestingly, a maximum photocurrent/dark current ratio was obtained when the operating voltage was reduced to around Vt. The time-response characteristics and sensitivity of the PTCDI-C13H27-based photosensor were investigated. Considerable interest has been focused on developing a flexible in-cell remote touch screen that should comprise photosensitive OTFTs and switch OTFTs simultaneously. In this work, both switch-OTFTs and photo-OTFTs can be formed on the flexible PES substrate by use of the same fabrication process. The electrical characteristics of switch-OTFTs under bending states are discussed in terms of photoluminescence and time-resolved photoluminescence measurements, as well as quantum theory calculations. [ABSTRACT FROM AUTHOR]

Electrical characteristics of pentacene-based ambipolar organic field-effect transistors (OFETs) are examined and are shown to significantly differ from those of unipolar OFETs. The electrical and hysteresis characteristics of the ambipolar OFETs depend on the applied source-drain bias and sweeping gate voltage range. The ambipolar OFET characteristics, such as charge mobility, subthreshold swing, threshold voltage, and off-current level, are controlled by the dual-carrier recombination and release process, through which opposite-sign charges can capture and release majority charges. This study contributes to advancing the development of more applications based on ambipolar OFETs. [ABSTRACT FROM AUTHOR]

This work concerns the electrical properties and carrier transport behavior of polycrystalline pentacene-based thin film transistors (TFTs) in air and high-vacuum environments. The transistor in a high vacuum outperforms that in air. The dependence of the field-effect mobility on the gate voltage and the drain voltage is considered. A potential barrier model is applied to estimate the trap density of the pentacene transistor. The determined trap density at the grain boundaries of the pentacene film in air exceeds that in a high vacuum. These results show that the increased trap concentration at the grain boundaries in ambient air limits carrier transport. [Copyright &y& Elsevier]

The luminescent properties of poly( p-phenylenevinylene) (PPV) blending with poly (ethylene glycol) (PEG) were investigated in terms of their structural formation during sample preparation. The blended systems were prepared from an aqueous solution of water-soluble poly (xylylene tetrahydrothiophenium chloride) (PPV precursor) mixed with PEG, followed by heat treatment to remove the tetrahydrothiophene groups from the PPV precursor. Structural analysis showed that PEG could react with PPV precursor to form C-O-C linkage and carbonyl groups in PPV chains, interrupting their conjugated length as suggested by their Infrared, Raman and UV/vis spectroscopes. Wide angle X-ray scattering (WARS) of blended systems also showed that PPV in blends had less packing. As to luminescent properties, the UV/vis and photoluminescent (PL) spectra show that the energy gap needed to produce the excitons increased along with the increase of PL intensity when PPV was blended with PEG. Similar results were also found for the EL properties of ITO/polyblends/Al devices. The EL light emission from blends was blue-shifted (compared to PPV) with a rather low threshold electric field strength. The EL performance of polyblends was better than that of pure PPV. Among them, the PPV-50PEG showed the highest EL intensity. The improved EL efficiency was attributed to the dilution effect, interrupted conjugated length, and lower packing of PPV chains. [ABSTRACT FROM AUTHOR]

Perovskite microwires have a larger surface-to-volume ratio and better photoelectric conversion efficiency than perovskite films. The degree of crystallization also affects the optoelectrical performances of perovskite microwires. Laser annealing was regarded as a tool for crystallization. High light absorption induced fast heating process. A 405 nm violet laser located near the absorption peak of typical perovskite films was employed as the annealing laser. In an in situ experimental design, the annealing laser beam was combined into the micro Raman measurement system. Real-time information of the annealing and crystallization was provided. Many excellent works were done, and typically needed offline optoelectronic measurements. An mW-level continuous-wave laser beam can provide enough kinetic energy for crystalline in perovskite microwires. The thermal distribution of the perovskite microwire under the annealing laser beams was considered here. Polarized Raman signals can provide evidence of the perovskite microwires crystallization. This work offered the novel approach of an on-site, real-time laser-induced thermal annealing design for perovskite microwires. This approach can be used in other material procedures. Intensity-dependent conditions were crucial for the annealing processes and analyzed in detail. The substrate effect was found. This proposed scheme provided integrated novel, scalable, and highly effective designs of perovskite-based devices. [ABSTRACT FROM AUTHOR]

The performance of bilayer heterojunction, pentacene and perylene tetracarboxylic diimide organic solar cells (OSC) is dramatically enhanced by performing nanoimprinting on the hole transport layer in which poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) nanogratings are built. A standard OSC embeded with PEDOT:PSS gratings enables photocarriers to move toward electrodes. In particular, the visualization of morphologies for these heterojunction layers reveals pillar-like grains that are induced by the geometric effect of PEDOT:PSS gratings. Toghther with analyzing absorption and time-resolved photoluminescence spectra, a consistent correlation between OSC performance, photophysical data, and pillar-like morphology has been obtained for the device with imprinted PEDOT:PSS nanogratings. [ABSTRACT FROM AUTHOR]

Polymorphism control of organic semiconductor films greatly affects optoelectronic device performance. The thin-film phase is always the dominant phase in the early growth of pentacene films; however, the performance of the bulk phase is superior to that of the thin-film phase. In the present study, a nanoimprinted polyimide layer is used to induce the growth of the bulk phase in the early stage. The bulk phase appears in the initial few layers and its dominance of the polymorphisms in the pentacene film increases with increasing thickness. The mechanism of the phase transformation is explained. [ABSTRACT FROM AUTHOR]

The authors report the suppression of the off-state leakage current and subthreshold swing (SS) in inkjet-printed poly(3-hexylthiophene) thin-film transistors with asymmetric work function source and drain electrodes. Indium tin oxide (ITO) material was used as source/drain electrodes and the source electrode was irradiated by KrF excimer laser. The dominant mechanisms for the suppressive Ioff could be attributed to the increase in the work function of ITO source irradiated by the excimer laser. Lower trap state density formed on the laser irradiated source electrode. Holes could be easily injected into the channel at small lateral electric field resulting in smaller threshold voltage and SS. [ABSTRACT FROM AUTHOR]

The authors have fabricated the pentacene thin films on polymethylmethacrylate (PMMA) and on silicon dioxide dielectric surfaces featuring similar surface energy and surface roughness. On both surfaces the pentacene films displayed high crystal quality from x-ray diffraction scans, although the film on PMMA had significantly smaller grain size. The pentacene transistors with PMMA exhibited excellent electrical characteristics, including high mobility of above 1.1 cm2/V s, on/off ratio above 106, and sharp subthreshold slope below 1 V/decade. The analysis of molecular microstructure of the pentacene films provided a reasonable explanation for the high performance using resonance micro-Raman spectroscopy. [ABSTRACT FROM AUTHOR]

Abstract: The organic complementary metal oxide semiconductor (O-CMOS) inverters were integrated with the p-type pentacene-based transistors and n-type N,N′-dioctyl-3,4,9,10-perylene tetracarboxylic diimide (PTCDI–C8H17)-based transistors. Polyimide (PI) films were inserted between the active layers and dielectrics as the role of surface modification. The performances of the O-CMOS including the mobility, on/off ratio, subthreshold slope, threshold voltage, gains, delay time, and leakage current suppression were dramatically enhanced when PI layer was introduced. An ideal O-CMOS inverter with the propagation delay time of 52μs at 1kHz was achieved for the device with PI modification layer. The detail mechanism for performance improvement was discussed. [Copyright &y& Elsevier]

Efficient and balanced pentacene-based ambipolar organic thin-film transistors (AmOTFTs) were prepared and ready for use to achieve simple fabrication of complementary-like inverters with high gains. We examined the effect of temperature on the electrical characteristics of pentacene-based AmOTFTs and corresponding complementary-like inverters. Such complementary-like inverters can perform nonpolar operations, such as first and third quadrant operations, and can work normally up to nearly 110 °C. In situ measurements demonstrated the excellent thermal stability of pentacene active layer at the corresponding temperatures. The operating principle of the ambipolar-based complementary-like inverters was also discussed. Given the ambipolar nature of pentacene active channel, the dual-carrier recombination and release processes governed the temperature-dependent switch behaviors of the inverters. A temperature-dependent linearity function was derived using the hysteresis switch voltage, thereby highlighting that pentacene-based ambipolar complementary-like inverters could potentially be employed in temperature sensors. Image 1 • High gain ambipolar pentacene-based organic complementary-like inverters. • The behaviors of electron–hole pairs governed the inverter switching properties. • The inverters exhibited a linear hysteresis switching–temperature relationship. • The potential application of the inverters as temperature sensors. [ABSTRACT FROM AUTHOR]

Abstract In organic electronic/photonic devices, numerous types of interfaces and their properties exhibit profound correlation with device performance. For optimizing the performance of organic electronic/photonic devices, appropriate and effective interface engineering needs to be developed. In this study, a high dielectric constant material, hafnium dioxide (HfO 2), and an organic semiconductor, N , N′ -ditridecyl-3,4,9,10-perylene tetracarboxylic diimide (PTCDI-C 13) were adopted as the dielectric and active layers, respectively, to fabricate low-voltage-driven organic thin-film transistors. Three kinds of insulating polymers were selected to serve as buffer layers (BLs) to modify HfO 2. After the addition of BLs onto HfO 2 , the insulating properties of HfO 2 and the microstructures of PTCDI-C 13 active layers improved, resulting in considerably enhanced electrical characteristics and stability of the devices. Among different polymeric BLs, the BL polymer exhibiting smaller interfacial tension with PTCDI-C 13 can induce PTCDI-C 13 to form better microstructures and generate lower interfacial trap density despite the rougher topography of polymeric BL, leading to improved electrical characteristics of the corresponding device. However, we observed that BL polymer with larger dipole moment of side groups can yield better electrical stability of the corresponding device under continuous operation compared with polymers with smaller interfacial tension. During long-term operation, the dipoles can be aligned by an electric field and form a strong dipole layer to facilitate charge accumulation and alleviate device degradation caused by bias-stress-induced trap/defect states. We further adopted a BL polymer with both small interfacial tension and large dipole moment to fabricate low-voltage-driven organic complementary inverters. The inverter can exhibit high electrical characteristics and stability during continuous operation. Interfacial tension and molecular dipole moment are possible important issues for effective interface engineering. Graphical abstract Image 1 Highlights • Polymeric buffer layers improve electrical performance of low-voltage-driven devices. • Polymeric buffer layers effectively improve the insulating property of HfO 2. • Small interfacial tension enhances electrical characteristics of devices. • Strong dipole moments of buffer layers increase electrical stability of devices. • Interfacial tension and dipole moment are important issues for organic devices. [ABSTRACT FROM AUTHOR]

The power conversion efficiency of solar cells can be optimized via an efficient charge collection by electrodes. In this study, a simple linear polyethylenimine (LPEI), which is an insulating polymer, was adopted as the cathode interfacial layer of poly(3-hexylthiophene) (P3HT):[6,6]-phenyl-C 61 -butyric acid methyl ester (PCBM)-based bulk-heterojunction organic solar cells (OSCs) with a non-inverted configuration. All photovoltaic parameters of the OSCs were significantly enhanced by depositing LPEI onto the oxygen plasma-treated P3HT:PCBM active layers. The causes of performance enhancement in OSCs were studied. Results revealed that the microstructure and morphology of the P3HT:PCBM layer were almost unaffected by the oxygen plasma treatment and the subsequent LPEI deposition. The X-ray photoelectron spectra of the specimens demonstrated that with the aid of oxygen plasma treatment, the linked LPEI molecules formed a well-aligned dipole layer on top of the P3HT:PCBM layer through the bonding of nitrogen (N) with oxygen (O). The results from quantum chemical calculations showed that the LPEI molecule with an N–O bond had a larger dipole moment at an appropriate direction than that without an N–O bond. By contrast, the LPEI molecules can form a dipole layer with a random orientation in the absence of N–O bonds. The conductive atomic force microscopy images of the specimens showed that the well-aligned dipole layer could facilitate electron transfer and could block hole transfer from the P3HT:PCBM to the cathodes. The well-aligned and augmented interface dipoles improved the charge selectivity at the cathodes and the photovoltaic performance of the devices. [ABSTRACT FROM AUTHOR]

Low-dimensional organic-inorganic hybrid perovskites possess unique microstructural, optical, and electrical properties and offer great application prospects in other fields in addition to optoelectronics. In this study, one-dimensional methylammonium lead iodide (MAPbI 3) nanowires (NWs) were fabricated using an antisolvent-assisted solution method with the addition of phenethylammonium iodide (PEAI). The effects of PEAI on the crystal growth, morphology and microstructure, photoluminescence (PL), and photoresponse performance of the NWs were investigated. The results showed that the addition of the appropriate amount of PEAI transformed the morphology of MAPbI 3 from micron-scale wires to elongated NWs with a high-aspect ratio. Scanning electron microscopy, X-ray diffraction, atomic force microscopy, scanning Kelvin probe microscopy, PL, and time-resolved PL spectroscopic characterizations were conducted, and the results confirmed that PEAI improved the microstructural properties of the as-prepared NWs and manifested surface passivation. The PEAI-treated MAPbI 3 NWs devices also exhibited a superior photoresponsivity as photodetectors compared with the untreated MAPbI 3 microwires devices. This study proposed a simple and effective method that can improve the microstructural and photoelectrical properties of low-dimensional MAPbI 3 crystals, which have a broad application potential for next-generation optoelectronic devices or detectors. • Nanowire-shaped MAPbI 3 with superior microstructural features were fabricated. • A novel approach of adding PEAI was presented to improve MAPbI 3 crystal properties. • PEAI-modified nanowires with larger crystallite size and smaller microstrain were obtained. • Emission and photoresponse properties were improved after PEAI treatment. • PEAI has a remarkable effect on the growth of low-dimensional MAPbI 3 crystals. [ABSTRACT FROM AUTHOR]