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An iminodibenzyl–quinoxaline–iminodibenzyl scaffold as a mechanochromic and dual emitter: donor and bridge effects on optical properties
摘要： The influence of phenyl linkage and donor strength on the photophysical properties of new derivatives of quinoxaline-containing iminodibenzyl and iminostilbene moieties is studied. The donor–acceptor derivatives showed dual thermally activated delayed fluorescence (TADF) and room temperature phosphorescence (RTP) despite a large energy gap between the excited singlet and triplet states (ca. 0.5 eV). This extremely rare observation is explained by the twisted and rigidified structure of the iminodibenzyl moiety.
关键词： dual emitter,quinoxaline,room temperature phosphorescence,iminodibenzyl,optical properties,mechanochromic,bridge effects,thermally activated delayed fluorescence,donor
更新于2025-09-19 17:15:36
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PCE11-based polymer solar cells with high efficiency over 13% achieved by room-temperature processing
摘要： With the emergence and rapid development of new non-fullerene acceptors (NFAs), bulk-heterojunction polymer solar cells (BHJ-PSCs) have achieved high power conversion efficiencies (PCEs) over 16%. Developing effective methods to fabricate high-performance thick-film PSCs is important to meet the requirements of the future roll-to-roll commercial production. PffBT4T-2OD (PCE11) as the most promising temperature-dependent aggregation (TDA) donor with high crystallinity has achieved high performance at high film thickness, which, however, needs at high processing temperature and is detrimental for practical production of large-area PSCs. We designed NFAs, ZITI-N-CH3, ZITI-N-C8H17, and ZITI-N-EH containing different side chains. Because of the excellent miscibility of the TDA-polymer PffBT4T-2OD and ZITI-N-R, the devices can be fabricated at room temperature, achieving a medium PCE of 8.78% for ZITI-N-CH3-based PSC, a high PCE of 12.13% for ZITI-N-C8H17-based PSC and a superior PCE of 13.07% for ZITI-N-EH-based PSC, which is attributed to the smallest domain size and highest crystallization for PffBT4T-2OD:ZITI-N-EH blend. The PCE of 13.07% is the highest among the TDA polymer-based PSCs, which can be maintained at 12.35% at the high thickness of 200 nm. This work provides an important guideline to develop high-performance thick-film TDA-polymer-based non-fullerene PSCs at mild processing conditions.
关键词： temperature-dependent aggregation,room-temperature processing,polymer solar cells,high efficiency,non-fullerene acceptors
更新于2025-09-19 17:13:59
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Low-Cost RoHS Compliant Solution Processed Photovoltaics enabled by Ambient Condition Synthesis of AgBiS2 Nanocrystals
摘要： Two major challenges exist before colloidal nanocrystal solar cells can take their place in the market: So far these devices are based on Pb/Cd containing nanocrystals and secondly the synthesis of these nanocrystals takes place in inert atmosphere at elevated temperatures due to the use of air-sensitive chemicals. In this report, a room-temperature, ambient-air synthesis for non-toxic AgBiS2 nanocrystals is presented. As this method utilizes stable precursors, the need for the use of a protective environment is eliminated, enabling the large-scale production of AgBiS2 nanocrystals. The production cost of AgBiS2 NCs at room temperature and under ambient conditions reduces by ~ 60 % compared to prior reports based on hot injection and the solar cells made of these nanocrystals yield a promising power conversion efficiency (PCE) of 5.5 %, the highest reported to date for a colloidal nanocrystal material free of Pb or Cd synthesized at room temperature and under ambient conditions.
关键词： semiconductors,room temperature,non-toxic,solar cells,nanocrystals
更新于2025-09-19 17:13:59
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Room temperature ferromagnetism in ball milled Cu-doped ZnO nanocrystallines: an experimental and first-principles DFT studies
摘要： Experimental and theoretical studies on the room temperature ferromagnetism of ball milled Zn0.95Cu0.05O nanocrystalline, were reported. X-ray diffraction analysis reveals that the most dominant crystalline phase is hexagonal wurtzite with presence of weak peaks due to Cu and CuO. Rietveld analysis indicated that the crystallite size decreases with increasing milling time, while the strain enhanced with milling time. Magnetic measurements using SQUID expose remarkable room temperature ferromagnetic ordering for milled samples. The physical origin of the ferromagnetism order has been explained using a bound magnetic polaron model. Theoretical calculations based on First principles methods were employed to calculate the electronic structures and magnetic properties of Cu doping and zinc and oxygen vacancies behavior of Zn1?xCuxO. It was found that a Cu dopant leads to induce magnetism and exhibits an increasing of magnetic moment when Zn vacancy are introduced.
关键词： Room temperature ferromagnetism,Ball milled Cu-doped ZnO,Magnetic properties,Nanocrystalline,First-principles DFT
更新于2025-09-19 17:13:59
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Trace level toxic ammonia gas sensing of single-walled carbon nanotubes wrapped polyaniline nanofibers
摘要： This paper presents a two-step enhancement and a comprehensive analysis of single-walled carbon nanotubes (SWCNTs) wrapped polyaniline nanofiber (NPANI) ammonia (NH3) gas sensor at room temperature. SWCNT-PANI composites are successfully synthesized using an efficient and cost-effective rapid in situ chemical polymerization method. The structural morphology and modification of the samples are characterized using field-emission scanning electron microscopy and HRTEM. FTIR and Raman spectroscopic studies are also performed to gain a better insight into the chemical environmental interaction in the as-prepared nanocomposite. The analysis confirms the successful formation of the nanocomposite. The observed NH3 gas-sensing response at 10 ppm of SWCNT, f-SWCNT (functionalised SWCNT), and SWCNT-PANI composite sensors are 5%–6%, 18%–20%, and 24%–25%, respectively. The SWCNT-PANI composite sensors have shown higher repeatability, selectivity, long-term stability, and fast response-recovery characteristics as compared to f-SWCNTs and pristine SWCNT sensors. Concentration and temperature dependent gas-sensing studies are also analyzed. The sensor response also shows a linear relationship with NH3 gas concentration and an inverse relationship with increasing temperature.
关键词： Raman spectroscopy,rapid in situ chemical polymerization,ammonia gas sensor,polyaniline nanofiber,field-emission scanning electron microscopy,FTIR,HRTEM,room temperature,single-walled carbon nanotubes
更新于2025-09-19 17:13:59
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[IEEE 2019 14th IEEE Conference on Industrial Electronics and Applications (ICIEA) - Xi'an, China (2019.6.19-2019.6.21)] 2019 14th IEEE Conference on Industrial Electronics and Applications (ICIEA) - Research and Application of Remote Removal of Floating Foreign Objects on Transmission Lines Based on Fiber Laser
摘要： We present a detailed investigation of the responsivity and the noise in room temperature THz direct detectors made of YBa Cu O (YBCO) thin-film nano-bolometers. The YBCO nano-bolometers are integrated with planar spiral antennas covering a frequency range from 100 GHz to 2 THz. The detectors were characterized at 1.6 THz, 0.7 THz, 400 GHz and 100 GHz. The maximum electrical responsivity of 70 V/W and a minimum noise equivalent power (NEP) of 50 pW/Hz were measured, whereas the highest optical responsivity was 45 V/W. The noise in nano-bolometers is independent on the device volume and for a given modulation frequency and a dc voltage Hz.
关键词： room temperature operation,YBa Cu O (YBCO) film,responsivity,THz detectors,Bolometer
更新于2025-09-19 17:13:59
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A phenobarbital containing polymer/ silica coated quantum dot composite for the selective recognition of mercury species in fish samples using a room temperature phosphorescence quenching assay
摘要： An analytical procedure using low-cost instrumentation (fluorescence/phosphorescence spectrophotometer) has been developed to assess total mercury in fishery products. Determinations were based on the room temperature phosphorescence (RTP) quenching of a composite Ph-QDs consisting of phenobarbital-containing polymer/silica coated Mn-doped ZnS quantum dots. Under optimum conditions (fish extract pH of 8.0, Ph-QDs concentration of 20 mg L?1, and an interaction time of 12 min), the material offers high selectivity for inorganic mercury and methyl-mercury over other common ions present in the fish matrix. Moreover, good linearity was obtained for mercury concentrations within the 0–100 μg L?1 range, and the obtained limit of detection (68.2 μg kg?1) is low enough for a reliable assessment of total mercury in fish and seafood samples. The developed method was found to be free of matrix effects, and offers the advantage that the fish extracts can be directly analysed even at a 1:10 dilution. The method was found to be accurate after analysing a fish certified reference material, and after comparing total mercury levels in a set of fish samples analysed by the proposed chemosensor probe and by inductively coupled plasma mass spectrometry after an acid decomposition sample pre-treatment.
关键词： Room temperature phosphorescence,Phenobarbital,Fish,Mercury,Quantum dots
更新于2025-09-19 17:13:59
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Room-temperature processed ZrO2 interlayer towards efficient planar perovskite solar cells
摘要： The Sn-doped In2O3 transparent conductive (ITO) electrode in planar perovskite solar cells (PSCs) is modified by zirconia (ZrO2) interlayer with low-temperature process. Here the ZrO2 film is prepared by ultraviolet (UV) treatment at room temperature. The effects of the inserted ZrO2 interlayer on the performance of CH3NH3PbI3-xClx-based PSCs have been systemically studied. After optimizing the process, the champion efficiency of PSC with UV-treated ZrO2 interlayer is 19.48%, which is larger than that of the reference PSC (15.56%). The improved performance in the modified devices is primarily ascribed to the reduced trap states and the suppressed carrier recombination at the ITO/SnO2 interface. Our work provides a facile route to boost the photovoltaic performance of PSCs by modifying the surface of transparent conductive electrode at room temperature.
关键词： Photoelectric properties,ITO/SnO2 interface modification,Ultraviolet (UV) treatment,Planar perovskite solar cell,Room-temperature processed ZrO2 interlayer
更新于2025-09-19 17:13:59
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Interface Engineering by Employing Zeolitic Imidazolate Framework-8 (ZIF-8) as the only Scaffold in the Architecture of Perovskite Solar Cells
摘要： In this study, we employed Zeolitic Imidazolate Framework-8 (ZIF-8) at the interlayer between the compact TiO2 and perovskite layers. As a result, enhanced perovskite crystallinity and grain sizes, and considerably improved photovoltaic performance of perovskite solar cell (PSC) were achieved. It was demonstrated that the ZIF-8 film includes all characteristics suitable for being applied as scaffold in the PSCs with the advantage of easier synthesis approach in room temperature in comparison to the mesoporous TiO2 counterpart. Moreover, we replaced the thermal annealing process commonly applied on the perovskite layers with room temperature ultrasonic vibration post treatment of wet perovskite films.
关键词： zeolitic imidazolate framework,Perovskite solar cells,room temperature,ultrasonic vibration post treatment,grain size
更新于2025-09-19 17:13:59
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In-Situ Tailoring of Vertically Coupled InAs p-i-p Quantum-Dot Infrared Photodetectors: Toward Homogeneous Dot Size Distribution and Minimization of Ina??Ga Intermixing
摘要： The authors report a detailed analysis of an epitaxial growth technique for Indium Arsenide (InAs) Quantum-dot infrared photodetectors to circumvent the detrimental effects arising from the progressively increasing dot-size in vertically coupled heterostructures. Constant overgrowth percentage of the vertically coupled dot-layers has been achieved with the implementation of the growth strategy, which has been validated by cross-sectional transmission electron microscopy (X-TEM) images of the samples. The optical characteristics of these samples have been analyzed through photoluminescence spectroscopy and photoluminescence excitation spectroscopy (PL and PLE) measurements which show longer wavelength response and reduced full width at half-maxima (FWHM) upon implementation of the growth strategy. X-TEM, in-plane and out-of-plane high resolution X-ray diffraction (HR-XRD) measurements suggest morphological improvement upon implementation of the growth strategy, with a reduction in the Indium desorption and lowering of defects and dislocation densities. Excellent correlation has been found between the different experimental results and also their theoretical simulations. The fabricated single-pixel photodetectors at low temperature (T=14K) show a broad response extending up to the MWIR region (~4.5μm) for one of the samples. Also, a strong spectral response in the SWIR region is obtained even at room temperature (T=300K). The highest responsivity (Rp) and specific detectivity (D*) values obtained are 166.17 A/W and 8.39 x 1010 cmHz1/2W-1 at a bias of 5V and 300K temperature.
关键词： p-i-p infrared photodetectors,InAs Quantum Dots,MBE growth strategy,homogenous dot size distribution,room temperature spectral response,In-Ga inter-diffusion
更新于2025-09-19 17:13:59