Search

The molecular template growth of the heterojunction was studied to tailor neuroplasticity that exhibits a high pair-pulse facilitation index of ~206%, and ultralow energy consumption of 0.54 fJ to mimic human-like optical synapse and memory functions.

A series of novel ABCBA-type miktoarm H-shaped copolymers with poly(3-hexylthiophene) segments have been synthesized and applied to phototransistor memory device materials, showing excellent memory properties and ductility/elasticity.

Magnetic resonance imaging is widely used to create detailed images of the organs and tissues. In daily clinical practice of diagnosing liver cirrhosis, it is still a challenge to find the best clinical diagnosis for detection hepatic lesions like hemangioma or hepatoma. In this study, we tried to compare the accuracy of method non-contrast enhancement multiparametric MRI (mpMRI) with conventional liver MRI. A total of 120 patients with liver cirrhosis were enrolled and were divided into two groups, 60 patients with hepatic hemangioma (HH, group A) and 60 patients with hepatocellular carcinoma (HCC, group B). MRI was first used for different diagnosis hepatic lesions without any invasive procedure or surgical treatment. All acquired MRI images were divided into 2 parts: the first part was the non-contrast enhancement multiparametric MRI (mpMRI), and the second part named the conventional liver MRI, was covered all images including non-contrast enhancement and dynamic contrast material-enhanced. The MRI images were interpreted by two experience gastrointestinal radiologists (I and II). Before analysis, the clinical manifestations, laboratory data, tissue biopsy results were not known. Paired samples t-test was used to analyze the significant difference of two-tailed probability (P < 0.05), and its Hemangioma and Hepatoma of receiver operating characteristic curve and area under the ROC curves values were evaluated. In the results, two-tailed probability of non-contrast enhancement mpMRI sequences and the conventional liver MRI in group A was found to be P = 0.109, while that in group B was found to be P = 0.115. After Wilcoxon sign-ranked test, the two-tailed probability reached 0.557 in group A, while that of group B reached 0.624; both showed not difference between the two groups. In conclusion, the non-contrast enhancement mpMRI that included the half-Fourier single-shot turbo spin-echo (HASTE) with fat suppression T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) and susceptibility-weighted imagining (SWI) sequence can provide reliable information for effectively differentiate HH and HCC without using contrast materials. This study is expected to provide a reference for the application of MRI in clinical diagnose for a better enhanced method.

Metal halide perovskite nanocrystals (PVSK NCs) are generally unstable upon their transfer from colloidal dispersions to thin film devices. This has been a major obstacle limiting their widespread application. In this study, we proposed a new approach to maintain their exceptional optoelectronic properties during this transfer by dispersing brightly emitting cesium lead halide PVSK NCs in polysaccharide-based maltoheptaose

With the explosive growth in data generation, photomemory capable of multibit data storage is highly desired to enhance the capacity of storage media. To improve the performance of phototransistor memory, an organic-molecule-based electret with an elaborate nanostructure is of great importance because it can enable multibit data storage in a memory device with high stability. In this study, a series of star-shaped rod-coil molecules consisting of perylenediimide (PDI) and biobased solanesol were synthesized in two-armed (PDI-Sol2), four-armed (PDI-Sol4), and six-armed (PDI-Sol6) architectures. Their molecular architecture-morphology relationships were investigated, and phototransistor memory was fabricated and characterized to evaluate the structure-performance relationship of these rod-coil molecules. Accordingly, the memory devices were enabled by photowriting with panchromatic light (405-650 nm) and electrical erasing using a gate bias. The PDI-Sol4-based memory device showed high memory ratios of 10 000 over 10 000 s and a rapid multilevel photoresponse of 50 ms. This achievement is related to the favorable energy-level alignment, isolated nanostructure, and face-on orientation of PDI-Sol4, which eliminated the charge tunneling barrier. The results of this study provide a new strategy for tailoring nanostructures in organic-molecule-based electrets by using a star-shaped rod-coil architecture for high-performance phototransistor memory.

Sequential regularity control on the n-type conjugated polymers was investigated in this work. The sequentially random polymer produced a near-amorphous structure and a strain-insensitive charge transport performance.

Three DPP-based dual-acceptor conjugated polymers comprising different proquinoidal heterocyclic acceptors are synthesized and their structure–property relationship using a transistor and their conductive states by doping are investigated.

A simple one-pot solution-processed OFET memory device has been fabricated based on the vertical phase separation of phthalocyanine-cored star-shaped polystyrene and an organic semiconductor.

The development of single-component organic solar cells (SCOSCs) using only one photoactive component with a chemically bonded D/A structure has attracted increasing research attention in recent years. At represent, most relevant studies focus on comparing the performance difference between a donor-acceptor (D-A) conjugated block copolymer (CBC) and the commensurate blending systems based on the same donor and acceptor segments, and still there are no reports on the impact of the segment ratio for a certain D-A CBC on the resultant photovoltaic performance. In this study, we synthesized a D-A all-conjugated polymers based on an n-type PNDI2T block and a p-type PBDB-T donor block but with three different segment ratios (P1-P3) and demonstrate the significance of the D/A segment ratio on photovoltaic performance. Our results reveal that the n-type PNDI2T block plays a more critical role in the inter/intra-chain charge transfer. P1 with a higher content of PNDI2T delivers superior exciton dissociation and charge transfer behavior than P2 and P3, benefitting from its more balanced hole/electron mobility. In addition, a higher packing regularity associated with a more dominant face-on orientation is also observed for P1. As a result, SCOSC based on P1 exhibits the highest PCE among the synthesized CBCs. It also possesses a minimal energy loss due to the better suppressed non-radiative recombination loss. This work provides the first discussion of the impact of the segment ratio for a D-A all-conjugated block copolymer and signifies the critical role of the n-type segment in designing high-performance single-component CBCs.

Three isoindigo–bithiophene conjugated polymers named P(Si–Si), P(Si–O), and P(Si–F) with the symmetric carbosilane and asymmetric carbosilane/oligoether, and carbosilane/semifluorinated side chains are investigated for thermoelectric application.

Tremendous research efforts have been dedicated into the field of photoresponsive nonvolatile memory devices owing to their advantages of fast transmitting speed, low latency, and power-saving property that are suitable for replacing current electrical-driven electronics. However, the reported memory devices still rely on the assistance of gate bias to program them, and a real fully photoswitchable transistor memory is still rare. Herein, we report a phototransistor memory device comprising polymer/perovskite quantum dot (QD) hybrid nanocomposites as a photoresponsive floating gate. The perovskite QDs offer an effective discreteness with an excellent photoresponse that are suitable for photogate application. In addition, a series of ultraviolet (UV)-sensitive insulating polymer hosts were designed to investigate the effect of UV light on the memory behavior. We found that a fully photoswitchable memory device was fulfilled by using the independent and sequential photoexcitation between a UV-sensitive polymer host and a visible light-sensitive QD photogates, which produced decent photoresponse, memory switchability, and highly stable memory retention with a memory ratio of 10

We demonstrate a transparent stretchable supercapacitor based on a nanocomposite electrode consisting of silver nanowires (AgNWs) and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:...

Biobased polymers have received extensive research attention in flexible and renewable electronics to meet the concept of environmental sustainability. In this study, we develop a series of new polyimides (PIs) from biosources to serve as the substrate and dielectrics for a flexible organic field-effect transistor (OFET). The bioderived diamine, (3R,6S)-hexahydrofuro[3,2-b]furan-3,6-diyl bis(4-aminobenzoate) (ISBA), synthesized from isosorbide (ISB), was reacted with three dianhydrides of pyromellitic dianhydride (PMDA), 3,3′,4,4′-biphenyl-tetracarboxylic dianhydride (BPDA), and cyclobutane-1,2,3,4-tetracarboxylic dianhydride (CBDA) to obtain PIs and copolyimides (Co-PIs) with a high biomass content up to 53%. These bioderived PIs possessed high Td’s over 400 °C and Tg’s over 250 °C. Furthermore, the CBDA-based and PMDA-based PIs exhibited CTE values below 50 ppm K–¹ due to the rigid heterocyclic ISB unit and the structural linearity of the CBDA and PMDA moieties in the polymer backbone. High transparency and low coloration were also observed in the biobased PIs. Finally, highly thermal-resistant PI(ISBA-C95B5) consisting of the CBDA/BPDA mole ratio of 95/5 was applied as the substrate and dielectrics in flexible OFET, demonstrating the compatible and stable performance even after being baked at 200 °C for 2 h or 1000 bending cycles. The present study reveals the potential application of biobased PIs in electronic devices for a sustainable economy.

To realize high-performance and intrinsically stretchable materials for field-effect transistor (FET) devices, a plethora of approaches about structure design have been explored. Herein, we report a new approach to control the carrier mobility–stretchability properties of the polymers by tuning the hydrophilicity and asymmetric side-chain combination. A series of isoindigo–bithiophene (II2T)-based semiconducting polymers with three kinds of side chains including carbosilane side chain, semifluorinated side chain, and oligoether side chain were synthesized for investigating the structure–mobility and structure–stretchability relationships. The experimental results showed that the molecular stacking pattern and orientation of the derived polymers could be controlled by altering the hydrophilicity and asymmetric side-chain combination. The side chains of carbosilane and oligoether and a semifluorinated side chain could provide an order edge-on stacking, conformability and backbone aggregation, and an irregular solid-state aggregation, respectively. Among them, P(Si–O) with oligoether and a carbosilane side chain exhibited an enhanced μₕ of 0.56 cm² V–¹ s–¹, edge-on stacking, and aggregation behavior owing to the favorable intermolecular interaction between the oligoether side chain and the asymmetric side chain to mitigate the steric hindrance. Also, P(Si–O) possessed a remarkable stretchability of (92%,⊥, 82%,∥) orthogonal μₕ retention under 100% strain and almost unchanged μₕ was observed after 1000 stretching–releasing cycles at 60% strain. The experimental results suggested that the combination and hydrophilicity of side chain played a pivotal role in developing semiconducting polymers with a high performance and an intrinsic stretchability.

The mechanical properties and structural design flexibility of charge-trapping polymer electrets have led to their widespread use in organic field-effect transistor (OFET) memories. For example, in the electrets of polyfluorene-based conjugated/insulating block copolymers (BCPs), the confined fiberlike polyfluorene nanostructures in the insulating polymer matrix act as effective hole-trapping sites, leading to controllable memory performance through the design of BCPs. However, few studies have reported intrinsically stretchable charge-trapping materials and their memory device applications, and a practical method to correlate the thin-film morphology of BCP electrets with their charge-trapping ability has not yet been developed. In this study, a series of new conjugated/insulating BCPs, poly(9,9-di-n-hexyl-2,7-fluorene)-block-poly(δ-decanolactone)s (PF-b-PDLx, x = 1-3), as stretchable hole-trapping materials are reported. The linear and branched PDL blocks with comparable molecular weights were used to investigate the effect of polymer architecture on morphology and device performance. Moreover, the coverage area of the polyfluorene nanofibers on the BCP films was extracted from atomic force microscopy images, which can be correlated with the trapping density of the polymer electrets. The branched PDL segments not only improve stretchability but also tailor crystallinity and phase separation of the BCPs, thus increasing their charge-trapping ability. The OFET memory device with PF-b-PDL3 as the electret layer exhibited the largest memory window (102 V) and could retain its performance at up to 100% strain. This research highlights the importance of the BCP design for developing stretchable charge-trapping materials.

Despite demonstrating higher photoluminescence quantum yield and better ambient and operational stability than organic–inorganic hybrid perovskites, all-inorganic perovskites encounter the problem of inferior film quality and interfacial electrical properties, which limits the resultant device performance. In this study, three polymers, P4a–c, bearing distinct pendant groups based on a similar conjugated group are synthesized and employed as an interlayer to modify the PEDOT:PSS/CsPbBr3 interface. Due to the pendant design, P4a–c possess deep-lying HOMO levels and high transparency across the visible range. The different structures of the pendant groups in P4a–c are shown to result in their different propensity in energy-level modulation and solid-state aggregation, which plays a non-trivial role in affecting the resulting device performance. Due to the more appropriate energy levels and better regulation of CsPbBr3 crystals, P4c with a polar bridge moiety is shown to better mediate the performance of the derived device. The P4c-mediated PeLED delivers six times enhanced luminance (Lmax, ∼36 000 cd m−2) and 3.6 times enhanced external quantum efficiency (EQE, 2.16%) as compared to the control device (∼6000 cd m−2, 0.60%). Notably, all the devices using P4a–c interlayers deliver a lower turn-on voltage than the control device, clearly revealing the positive role of P4a–c interlayers on diminishing the barrier across the associated interface to improve charge injection efficiency.