- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Multi-scale ordering in highly stretchable polymer semiconducting films
摘要： Stretchable semiconducting polymers have been developed as a key component to enable skin-like wearable electronics, but their electrical performance must be improved to enable more advanced functionalities. Here, we report a solution processing approach that can achieve multi-scale ordering and alignment of conjugated polymers in stretchable semiconductors to substantially improve their charge carrier mobility. Using solution shearing with a patterned microtrench coating blade, macroscale alignment of conjugated-polymer nanostructures was achieved along the charge transport direction. In conjunction, the nanoscale spatial confinement aligns chain conformation and promotes short-range π–π ordering, substantially reducing the energetic barrier for charge carrier transport. As a result, the mobilities of stretchable conjugated-polymer films have been enhanced up to threefold and maintained under a strain up to 100%. This method may also serve as the basis for large-area manufacturing of stretchable semiconducting films, as demonstrated by the roll-to-roll coating of metre-scale films.
关键词： charge carrier mobility,conjugated polymers,solution shearing,stretchable semiconductors,roll-to-roll coating,multi-scale ordering
更新于2025-11-19 16:56:35
-
Admittance of Organic LED Structures with an Emission YAK-203 Layer
摘要： The current-voltage characteristics and admittance of multilayer structures for organic LEDs based on the PEDOT:PSS/NPD/YAK-203/BCP system have been experimentally investigated in a wide range of the measurement conditions. It is shown that at voltages corresponding to the effective radiative recombination of charge carriers, a significant decrease in the differential capacitance of the structures is observed. The frequency dependences of the normalized conductance of LED structures are in good agreement with the results of numerical simulation in the framework of the equivalent circuit method. Changes in the frequency dependences of the admittance with a change in temperature are most pronounced in the temperature range of 200–300 K and less noticeable in the temperature range of 8–200 K. From the frequency dependences of the imaginary part of impedance, the charge carrier mobilities are found at various voltages and temperatures. The mobility values obtained by this method are somewhat lower than those determined by the transient electroluminescence method. The dependence of the mobility on the electric field is well approximated by a linear function. As the temperature decreases from 300 to 220 K, the mobility decreases several times.
关键词： frequency dependence of imaginary part of impedance,LED structure,current-voltage characteristic,transient electroluminescence,organic semiconductor,charge carrier mobility,method of equivalent circuits,admittance
更新于2025-11-14 17:28:48
-
Potential and limitations of CsBi3I10 as photovoltaic material
摘要： Herein we demonstrate the dry synthesis of CsBi3I10 both as free-standing material as well as in the form of homogeneous thin films, deposited by thermal vacuum deposition. Chemical and optical characterization shows high thermal stability, phase purity, and photoluminescence centered at 700 nm, corresponding to a bandgap of 1.77 eV. These characteristics make CsBi3I10 a promising low-toxicity material for wide bandgap photovoltaics. Nevertheless, the performance of this material as a semiconductor in solar cells remains rather limited, which can be at least partially ascribed to a low charge carrier mobility, as determined from pulsed-radiolysis, time-resolved microwave conductivity. Further developments should focus on understanding and overcoming the current limitations in charge mobility, possibly by compositional tuning through doping and/or alloying, as well as optimizing thin film morphology which may be another limiting factor.
关键词： photovoltaic material,thermal vacuum deposition,CsBi3I10,dry synthesis,charge carrier mobility
更新于2025-09-23 15:21:01
-
Synergistic enhancement in the microelectronic properties of poly-(dioctylfluorene) based Schottky devices by CdSe quantum dots
摘要： This paper reports the potential application of cadmium selenide (CdSe) quantum dots (QDs) in improving the microelectronic characteristics of Schottky barrier diode (SBD) prepared from a semiconducting material poly-(9,9-dioctylfluorene) (F8). Two SBDs, Ag/F8/P3HT/ITO and Ag/F8-CdSe QDs/P3HT/ITO, are fabricated by spin coating a 10 wt% solution of F8 in chloroform and 10:1 wt% solution of F8:CdSe QDs, respectively, on a pre-deposited poly(3-hexylthiophene) (P3HT) on indium tin oxide (ITO) substrate. To study the electronic properties of the fabricated devices, current-voltage (I–V) measurements are carried out at 25 °C in dark conditions. The I–V curves of Ag/F8/P3HT/ITO and Ag/F8-CdSe QDs/P3HT/ITO SBDs demonstrate asymmetrical behavior with forward bias current rectification ratio (RR) of 7.42 ± 0.02 and 142 ± 0.02, respectively, at ± 3.5 V which confirm the formation of depletion region. Other key parameters which govern microelectronic properties of the fabricated devices such as charge carrier mobility (μ), barrier height (φb), series resistance (Rs) and quality factor (n) are extracted from their corresponding I–V characteristics. Norde’s and Cheung functions are also applied to characterize the devices to study consistency in various parameters. Significant improvement is found in the values of Rs, n, and RR by 3, 1.7, and 19 times, respectively, for Ag/F8-CdSe QDs/P3HT/ITO SBD as compared to Ag/F8/P3HT/ITO. This enhancement is due to the incorporation of CdSe QDs having 3-dimensional quantum confinement and large surface-to-volume area. Poole-Frenkle and Richardson-Schottky conduction mechanisms are also discussed for both of the devices. Morphology, optical bandgap (1.88 ± 0.5 eV) and photoluminescence (PL) spectrum of CdSe QDs with a peak intensity at 556 nm are also reported and discussed.
关键词： poly-(9,9-dioctylfluorene),charge carrier mobility,Schottky barrier diode,microelectronic properties,CdSe quantum dots
更新于2025-09-23 15:19:57
-
Hall Effect in Germanium Doped with Different Impurities
摘要： The influence of different impurities on the kinetics of electronic processes in n-Ge?Sb? single crystals is investigated. A substantial decrease in the charge carrier mobility in the region of predominantly impurity scattering (at 77 K) in n-Ge?Sb + Si? crystals, as well as in germanium crystals doped with the rare-earth elements, is detected, and this effect is explained.
关键词： Hall effect,charge carrier mobility,germanium,Hall coefficient,impurities
更新于2025-09-19 17:15:36
-
Naphthalene and perylene diimides – better alternatives to fullerenes for organic electronics?
摘要： The LUMO levels of rylene diimides are highly comparable to those of fullerenes but this class of molecules offers tunability of both HOMO and LUMO levels and the related band gap by either simple substitution at the aromatic core or annulation to give expanded p-scaffolds. In this article we highlight the most outstanding achievements during the last decade in terms of charge carrier mobility for organic thin-film and single crystal field-effect transistors as well as photovoltaic performance for both small molecule and polymeric compounds.
关键词： fullerenes,perylene diimides,organic electronics,photovoltaic performance,naphthalene diimides,charge carrier mobility
更新于2025-09-19 17:15:36
-
Elucidation of Donor:Acceptor Phase Separation in Nonfullerene Organic Solar Cells and Its Implications on Device Performance and Charge Carrier Mobility
摘要： In bulk-heterojunction solar cells, the device performance strongly depends on the donor and acceptor properties, the phase separation in the absorber layer, and the formation of a bicontinuous network. While this phase separation is well explored for polymer:fullerene solar cells, only little is known for polymer:nonfullerene acceptor solar cells. The main hurdle in this regard is often the chemical similarity of the conjugated polymer donor and the organic nonfullerene acceptor (NFA), which makes the analysis of the phase separation via atomic force microscopic (AFM) phase images or conventional transmission electron microscopy difficult. In this work, we use the donor polymer PTB7-Th and the small molecule acceptor O-IDTBR as the model system and visualized the phase separation in PTB7-Th:O-IDTBR bulk-heterojunctions with different donor:acceptor ratios via scanning transmission electron microscopy (STEM) high-angle annular dark-field (HAADF) images and electron energy loss spectroscopy (EELS) based elemental mapping, which resulted in a good contrast between the donor and the acceptor despite very low differences in the chemical composition. AFM as well as grazing-incidence wide-angle X-ray scattering (GIWAXS) investigations support the electron microscopic data. Furthermore, we elucidate the implications of the phase separation on the device performance as well as charge carrier mobilities in the bulk-heterojunction layers, and a high performance of the solar cells was found over a relatively broad range of polymer domain sizes. This can be related to the larger domain sizes of the acceptor phase with higher amounts of O-IDTBR in the blend, while the polymer donor phase still forms continuous pathways to the electrode, which keeps the hole mobility at a relatively constant level.
关键词： nanomorphology,organic photovoltaics,charge carrier mobility,bulk-heterojunction,scanning transmission electron microscopy
更新于2025-09-19 17:13:59
-
High-Efficiency Nonfullerene Organic Solar Cells Enabled by 1000 nm Thick Active Layers with a Low Trap-State Density
摘要： The high-efficient organic solar cells (OSCs) with thicker active layers are potential candidates for large-area solar panels fabrication. The low charge carrier mobility of the photoactive materials has been identified as the major problem hindering photovoltaic performance of the thick-film OSCs. In this study, high performance of ultra-thick film organic solar cells employing a non-fullerene acceptor BTP-4Cl and a polymer donor PBDB-TF is demonstrated. Two blends (PBDB-TF:BTP-4Cl and PBDB-TF:IT-4F) show comparable mobilities and excellent photovoltaic characteristics in thin-film devices; while in the 1000-nm-thick devices, although they both exhibit desirable and balanced mobilities, the PBDB-TF:BTP-4Cl-based blend possesses lower trap-state density than the IT-4F-based counterpart, leading to lower trap-assist recombination, longer carrier lifetime, and thus a much higher short circuit current density in the device. As a result, the BTP-4Cl-based 1000-nm-thick OSC achieves a remarkable PCE of 12.1%, which greatly outperforms the IT-4F-based devices (4.72%). What is more, for a 1000-nm thick device with active area of 4 cm2, a promising efficiency of 10.1% was obtained, showing its great potential in future large-scale production.
关键词： trap-state density,ultra-thick active layers,high efficiency,non-fullerene organic solar cells,charge carrier mobility
更新于2025-09-19 17:13:59
-
Photo- and electroluminescence features of films and field effect transistors based on inorganic perovskite nanocrystals embedded in a polymer matrix
摘要： The optical and electrical properties of films and field-effect transistors (FETs) based on pure MEH-PPV, neat CsPbBr3 nanocrystals (NCs), and MEH-PPV:CsPbBr3 NCs composites with different contents of CsPbBr3 NCs are investigated. The films were characterized by absorbance, atomic-force microscope and current-voltage characteristics (I-Vs) techniques. Relative PL and EL intensities and PL spectra of the pure MEH-PPV, neat CsPbBr3 NCs and MEH-PPV:CsPbBr3 NCs films were measured at 300 K at various levels of optical and electrical excitation power; these dependencies of the PL and EL intensities turned out to be sublinear and superlinear respectively. FETs based on MEH-PPV:CsPbBr3 NCs (1:1) films exhibit I-Vs at 290 – 100 K a dominant hole transport mechanism. The mobility of charge carriers was determined at 290 K for neat CsPbBr3 NCs (for electrons: 2.7 10-2 cm2/Vs) and MEH-PPV:CsPbBr3 NCs (1:1) (for holes: 9 cm2/Vs). The temperature dependence of the hole mobility μFET(T) of FETs based on MEH-PPV:CsPbBr3 NCs (1:1) films characteristic of the hopping mode. It was found that the superlinearity of the dependence of EL of MEH-PPV:CsPbBr3 NCs LE-FETs at 290 K increases with increasing concentration of CsPbBr3 NCs due to efficient energy transfer between CsPbBr3 NCs and the MEH-PPV polymer matrix, and also because of the probability of electron tunneling through the potential barrier to electrode. It is expected that the obtained MEH-PPV:CsPbBr3 NCs nanocomposite films will be useful for efficient applications in nanotechnology LEDs, FETs and LE-FETs.
关键词： Energy transfer,Field-effect transistors,Semiconducting polymers,Photo- and electroluminescence,Charge carrier mobility,Inorganic perovskite nanocrystals
更新于2025-09-16 10:30:52
-
A Random Polymer Donor for High-Performance Polymer Solar Cells with Efficiency Over 14%
摘要： Constructing random copolymers has been regarded as an easy and effective approach to design polymer donors for state-of-the-art polymer solar cells (PSCs). In this work, we develop a naphtho[2,3-c]thiophene-4,9-dione (NTDO) based copolymer PBN-Cl as a donor material for PSC, and a moderate power conversion efficiency (PCE) of 11.21% is achieved with a relatively low fill factor (FF) of 0.615. We then incorporate a similar acceptor unit benzo[1,2-c:4,5-c′]dithiophene-4,8-dione (BDD) into the polymeric backbone of PBN-Cl to tune its photovoltaic performance, and a significantly higher PCE of 14.05% is achieved from the random polymer PBN-Cl-B80 containing 80% BDD unit. The enhanced PCE of the PBN-Cl-B80-based device mainly relies on the higher FF value, resulting from the improved charge mobility properties, reduced bimolecular and trap-assisted recombination, and more appropriate phase separation. The results demonstrate a feasible strategy to tune the photovoltaic performance of polymer donors by constructing random polymer with a compatible component.
关键词： polymer solar cells,power conversion efficiency,random polymer,fill factor,charge-carrier mobility,polymer donor
更新于2025-09-16 10:30:52