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The redox activities of polyaniline (PANI) are hindered by the instability of pernigraniline salt (PS) state which degrades into oligo‐aniline. In this work, the use of protic additives is examined to mitigate capacity fading and increase utilization of PANI in nonaqueous electrolytes. The protic additive propylene glycol, with its hydrogen‐bonding capabilities, stabilizes the PS PANI and promotes reversible redox reactions, facilitating high capacity and an extended cycle lifetime for applications in metal ion supercapacitors. The use of this protic nonaqueous electrolyte in a PANI–zinc device results in an energy density of 255 Wh kg−1 at a power density of 1.8 kW kg−1 and a robust cycle lifetime of 3,850 charge/discharge cycles. The PANI at a high current density of 6.5 mA cm−2 reaches a capacity of 257 mAh g−1, equivalent to 87% of the its theoretical capacity, showcasing the effectiveness of the protic additive in improving both capacity and cycle life in electrochemical supercapacitors. [ABSTRACT FROM AUTHOR]

The development of portable X‐ray detectors is necessary for diagnosing fractures in unconscious patients in emergency situations. However, this is quite challenging because of the heavy weight of the scintillator and silicon photodetectors. The weight and thickness of X‐ray detectors can be reduced by replacing the silicon layer with an organic photodetectors. This study presents a novel bithienopyrroledione‐based polymer donor that exhibits excellent photodetection properties even in a thick photoactive layer (~700 nm), owing to the symmetric backbone and highly soluble molecular structure of bithienopyrroledione. The ability of bithienopyrroledione‐based polymer donor to strongly suppress the dark current density (Jd ~ 10−10 A cm−2) at a negative bias (−2.0 V) while maintaining high responsivity (R = 0.29 A W−1) even at a thickness of 700 nm results in a maximum shot‐noise‐limited specific detectivity of Dsh* = 2.18 × 1013 Jones in the organic photodetectors. Printed organic photodetectors are developed by slot‐die coating for use in X‐ray detectors, which exhibit Dsh* = 2.73 × 1012 Jones with clear rising (0.26 s) and falling (0.29 s) response times upon X‐ray irradiation. Detection reliability is also proven by linear response of the X‐ray detector, and the X‐ray detection limit is 3 mA. [ABSTRACT FROM AUTHOR]

III‐V quantum dots (QDs) have emerged as significant alternatives to Cd‐ and Pb‐based QDs, garnering notable attention over the past two decades. However, the understanding of III‐V QDs, particularly in the short wave‐infrared (SWIR) region, remains limited. InAs QDs are widely recognized as the most prominent SWIR QDs, but their absorption beyond 1400 nm presents various challenges. Consequently, InSb QDs with relatively narrower bandgaps have been investigated; however, research on their device applications is lacking. In this study, InSb QDs are synthesized with absorption ranging from 1000 to 1700 nm by introducing Cl− ions to enhance QD surface stability during synthesis. Additionally, it coated InAs and ZnSe shells onto the InSb QDs to validate photoluminescence in the SWIR region and improve photostability. Subsequently, these QDs are employed in the fabrication of photodetector devices, resulting in photodetection above 1500 nm using Pb‐free QDs. The photodetection device exhibited an external quantum efficiency (EQE) of 11.4% at 1370 nm and 6.3% at 1520 nm for InSb core QDs, and 4.6% at 1520 nm for InSb/InAs core/shell QDs, marking the successful implementation of such a device. In detail, the 1520 nm for InSb core device showed a dark current density(JD) value of: 1.46 × 10−9 A/cm2, responsivity(R): 0.078 A/W, and specific detectivity based on the shot noise(Dsh*): 3.6 × 1012 Jones at 0 V. [ABSTRACT FROM AUTHOR]

Poly(3,4-ethylenedioxythiophene) doped with poly (4-styrenesulfonate acid) (PEDOT:PSS), well-known as the most remarkable conducting polymer, has been applied in many areas due to its high electrical conductivity, high transparency, low cost, good flexibility and film formation property and excellent thermal stability. However, the strong acidity and insulating properties of PSS with high hydrophilicity can lead to significant deterioration of optoelectronic device performance. Here, we report the synthesis and study of fluorinated copolymers containing PSS called PSS-co-TF towards mitigating the above limitations. The resultant copolymers provide enhanced electrical conductivity and hydrophobicity to the PEDOT:PSS-co-TF composites compared to PEDOT:PSS even while sustaining good surface morphology. The influence of p-type buffer layers of PEDOT:PSS-co-TF composites on the performance of organic photodetectors made from poly(3-hexylthiophene) and PC[61]BM blends has been investigated. Among them, the device using PEDOT:PSS-co-TF3 exhibited the highest detectivity of 3.46 × 1012 Jones at −0.5 V in response to 510 nm light, attributed to the enhanced electrical conductivity. [ABSTRACT FROM AUTHOR]

Ultra-flexible organic photovoltaics (OPVs) are promising candidates for next-generation power sources owing to their low weight, transparency, and flexibility. However, obtaining ultra-flexibility under extreme repetitive mechanical stress while maintaining optical transparency remains challenging because of the intrinsic brittleness of transparent electrodes. Here, we introduce strain-durable ultra-flexible semitransparent OPVs with a thickness below 2 μm. The conformal surface coverage of nanoscale thin metal electrodes (< 10 nm) is achieved, resulting in extremely low flexural rigidity and high strain durability. In-depth optical and electrical analyses on ultrathin metal electrodes showed that the devices maintain over 73% of their initial efficiency after 1000 cycles of repetitive compression and release at 66% compressive strain, and the average visible light transmittances remain higher than 30%. To our knowledge, this is the first systematical study on mechanical behaviors of strain-durable ultra-flexible ST-OPVs through precise adjustment of each ultrathin electrode thickness toward the emergence of next-generation flexible power sources. [ABSTRACT FROM AUTHOR]

A series of conjugated polymers (CPs) sharing the same conjugated framework were designed to investigate their detection capability of near infrared light (1000 nm). Through engineering of the CP side-chains, both the light harvesting efficiency and the degree of dark current, which are crucial parameters for determining the performance of photo-detectors, were intercorrelated with the miscibility of CP with n-type PC71BM and the energy level configuration of the inverted-type device architecture. Based on the morphological analysis of the active layer, 2EO-PDBF, containing ethylene glycol units in the side-chain, was found to form enlarged CP:PC71BM interfaces, resulting in superior photo-responsivity compared to other CPs bearing aliphatic side chains. In addition, it was verified that the relatively shallow lowest energy level (LUMO) of 2EO-PDBF suppressed the generation of dark current by serving as an energetic barrier against electron injection from the Ag electrode. Consequently, due to both the reduced dark current and ameliorated photocurrent in 2EO-PDBF compared to those of other CPs with the same conjugated framework, a superior photo-detectivity exceeding 2 × 1012 Jones was attained at 1000 nm with a rapid response time (350 and 410 μs for the rise and decay times, respectively). The obtained results clearly provide plausible design strategies for CPs to limit the dark current and to improve the light harvesting efficiencies of organic photo-detectors. [ABSTRACT FROM AUTHOR]