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P3HT with Zn(C <sub/>6</sub> F <sub/>5</sub> ) <sub/>2</sub> as p‐Type Dopant for the Enhanced Performance of Planar Perovskite Solar Cells
摘要： The molecular organic Lewis acid bis(pentafluorophenyl)zinc [Zn(C6F5)2] is reported as an efficient p-type dopant for poly(3-hexylthiophene-2,5-diyl) (P3HT), to be used as hole-transporting material (HTM) in perovskite solar cells (PSCs) for the first time. To date, the most efficient PSCs use lithium bis(trifluoromethane) sulfonimide lithium salt (LiTFSI) and 4-tert-butylpyridine (tBP) as standard additives for HTMs. However, such dopants can induce deleterious effects on device stability. Herein, the effect of the concentration of Zn(C6F5)2 in P3HT HTM on the performance of PSCs is investigated. The P3HT-based PSCs using a low concentration of the dopant (0.025 mol%) in the HTM layer exhibit the best performance and the highest power conversion efficiency (PCE) of 17.49%, which is almost 3.5% higher than the achieved PCE for pristine P3HT-based PSCs. The origin of the improved performance for PSCs is further investigated, by studying the conductivity and hole mobility of the thin films based on pristine and doped P3HT. Adding a small amount of Zn(C6F5)2 to P3HT increases its thin-film hole mobility and its hole extraction ability.
关键词： Lewis acid dopants,poly(3-hexylthiophene-2,5-diyl),perovskite solar cells,hole-transporting materials
更新于2025-09-19 17:13:59
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Metal-free carbon nitride with boosting photo-redox ability realized by the controlled carbon dopants
摘要： Metal-free carbon nitride with controlled carbon dopants (ACCN) was synthesized by one-step copolymerization of dicyandiamide (DCD) and ammonium citrate (AC). The obtained ACCN possesses narrower band gap compared to pure graphitic carbon nitride (CN), contributing to broader utilization region of visible light. It exhibits downshifted conduction band and valence band potential with the increased addition of AC. Carbon atoms replace the bridging nitrogen atoms in the framework of ACCN during calcination process, which greatly increase its electrical conductivity and charge separation efficiency. In addition, nitrogen defects and some carbon species linked to the introduced carbon atoms are detected in ACCN. They can also serve as electrons sink to promote the separation of electron-hole pairs. As a consequence, ACCN possesses improved redox ability in the degradation of sulfamethazine (SM2) under visible light. The removal ratio by optimal ACCN achieves 81% in 60 min and its reaction apparent rate constant (0.0277 min?1) is 6.6 times higher than that of CN (0.0042 min?1). Furtherly, the mechanism and reaction process during the photocatalytic degradation are studied specifically. This work provides a facile and green strategy to prepare nonmetal modified CN with boosting photo-redox ability for pollutants treatment.
关键词： g-C3N4,Charge separation,Photocatalysis,Carbon dopants,Pollutants degradation,Ammonium citrate
更新于2025-09-16 10:30:52
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Modulation doping of absorbent cotton derived carbon dots for quantum dot-sensitized solar cells
摘要： In order to improve the power conversion efficiency (PCE) of quantum dot-sensitized solar cells (QDSC), a series of absorbent cotton derived carbon quantum dots (CQDs) with different dopants (namely carbamide, thiourea, and 1,3-diaminopropane) have been successfully synthesized by a one-pot hydrothermal method. The average particle sizes of the three doped CQDs are 1.7 nm, 5.6 nm, and 1.4 nm respectively, smaller than that of the undoped ones (24.2 nm). The morphological and structural characteristics of the four CQDs have been studied in detail. In addition, the three doped CQDs exhibit better optical properties compared with the undoped ones in the UV-vis and PL spectra. Then CQD-based QDSC are experimentally fabricated, showing that the short current density (Jsc) and open circuit voltage (Voc) of the QDSC are distinctly improved owing to the dopants. Especially the QDSC with the 1,3-diaminopropane doped CQD achieves the highest PCE (0.527%), 299% larger than that without dopant (0.176%). In order to highlight a reasonable mechanism, the UV-vis diffuse reflectance spectrum of CQD sensitized TiO2 and the calculated energy band structures of various CQDs are investigated. It’s found from the above analysis that the addition of carbamide, thiourea, and 1,3-diaminopropane is beneficial to obtain CQDs of smaller size, and with a smaller band gap and more nitrogenous or sulphureous functional groups, which enhance the light absorption performance and photo-excitation properties. The above factors are helpful to improve the Jsc of QDSC. Nitrogen, acting as a donor to the CQDs, will assist the sensitized photoanode with a higher Fermi level, resulting in a larger Voc of the QSDC. Finally this study builds the relation among the microstructure of the CQDs, three characteristics of the CQDs (namely the spectra, energy band structure and functional groups) and the photoelectric properties of the QDSC, which will provide guidance for the modulation doping of CQDs to improve the PCE of QDSC.
关键词： dopants,carbon quantum dots,hydrothermal method,power conversion efficiency,quantum dot-sensitized solar cells
更新于2025-09-16 10:30:52
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The effect of Ga doping on ZnO thin films subjected to CO2 laser annealing
摘要： The effect of Ga dopant on ZnO thin films was studied for transparent conducting oxide (TCO) applications. In and Ga were selected as dopants for the ZnO thin films, and their mole ratios were varied to identify the optimum proportions of the two dopants. After doping, optical post-annealing processes were applied to improve the conducting properties of the films. By applying optical post-annealing processes, rapid thermal annealing and CO2 laser annealing, the dopants were ionized and thus contributed to the conducting process. The crystal and electrical properties were studied and analyzed. By determining the films’ absorption and transmittance properties, their energy band gaps were calculated, and through X-ray photoelectron spectroscopy analysis, we found that the Ga dopant plays an important role in the TCO behavior. The Ga dopant in the ZnO thin films that had undergone laser annealing improved the electrical conductance properties due to their contributing the oxygen vacancy concentration, increasing the amount of free electrons in the ZnO structure.
关键词： In and Ga dopants,transparent conducting oxides,ZnO
更新于2025-09-16 10:30:52
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The Impact of Mobile Ions on the Steady State Performance of Perovskite Solar Cells
摘要： Mobile ions in perovskite solar cells induce many unique transient phenomena, while their influence under steady-state, the primary operating condition, has received little attention. Therefore, in this work we employ ionic-drift diffusion models to assess how the steady-state distribution of mobile ions affects the photogenerated carrier collection, and their redistribution due to dopants and energy band alignment. We demonstrate that mobile ions can transform the carrier transport mechanism from a combination of drift and diffusion to transport by diffusion only, which only impacts the device efficiency if the carrier mobility-lifetime product is limited due to increased transport losses and changed recombination dynamics. A high concentration of dopants is also required in perovskite devices for such doping to have a measurable impact while the energy alignment of the transport layers, on the other hand, can in principle result in a doping-like effect, which generally causes adverse consequences for cell efficiency.
关键词： dopants,steady-state performance,perovskite solar cells,energy band alignment,mobile ions,carrier transport
更新于2025-09-12 10:27:22
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[IEEE 2019 IEEE International Conference on System, Computation, Automation and Networking (ICSCAN) - Pondicherry, India (2019.3.29-2019.3.30)] 2019 IEEE International Conference on System, Computation, Automation and Networking (ICSCAN) - Improvisation on NiO based Thin Film Solar Cell Conversion Efficiency by the Addition of Dopants
摘要： There is a growing need for the development of thin film flexible solar cells with improved efficiency based on the market demand. This review article helps to compare nickel oxide based thin films with other metal oxides which are used to make thin film solar cells. CdS/CdTe, CIGS and GaAs based thin film solar cells also discussed and compared their efficiencies with metal oxide based solar cells. Various processing methods used for the preparation of thin films are discussed in the literature review part and the suitable method for making thin films are proposed. The work carried out so far with the addition of dopants such as Sr, Cu, Ag, Y, Au and Li concentration in nickel oxide layer was discussed. Thin film solar cell efficiencies with and without dopants in NiO layer are compared in a detailed manner in this article. The efficiencies of doped and undoped NiO based thin film solar cells with single crystal silicon solar cells are also compared.
关键词： metal oxides,dopants,thin films,efficiencies
更新于2025-09-12 10:27:22
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Highly efficient perovskite solar cell utilizing a solution-processable tetrabenzoporphyrin hole transport material with p-type dopants
摘要： We demonstrate an efficient hole transporting material (HTM), soluble non-peripherally substituted octahexyl tetrabenzoporphyrin (C6TBPH2), for perovskite solar cells and determine the role of p-type dopants in improving the photovoltaic performance of devices utilizing this C6TBPH2 HTM. By adding p-type dopants, the fill factor and short-circuit current density under a reverse bias scan are improved from 0.20 ± 0.02 to 0.66 ± 0.03 and from 15 ± 2 to 20.8 ± 0.1 mA cm?2, respectively, due to formation of oxidized C6TBPH2 radical cations. Hence, the devices utilizing C6TBPH2 HTM achieve power conversion efficiencies of 15.2%, which are comparable with devices utilizing commercial HTMs fabricated under similar conditions.
关键词： perovskite solar cell,hole transport material,tetrabenzoporphyrin,photovoltaic performance,p-type dopants
更新于2025-09-11 14:15:04
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Defect process and lithium diffusion in Li2TiO3
摘要： Lithium metatitanate, Li2TiO3, is a material that is being considered for the breeder blanket region of fusion reactors, and as a cathode material in lithium batteries. We employ atomistic simulations to study the point defect processes and lithium diffusion in Li2TiO3. It is calculated that the activation energy of migration of Li ions via the vacancy mechanism is 0.51 eV along the ab plane. The energetically favorable intrinsic defect type is Li Frenkel (1.25 eV/defect). This is important as the formation of Li vacancies is required as they act as vehicles for Li diffusion in the vacancy mechanism. The solution of trivalent dopants can contribute further Li vacancies, however, the synthesis routes should be determined experimentally.
关键词： Li diffusion,Li2TiO3,Defects,Dopants
更新于2025-09-11 14:15:04
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Point defects and dopants of boron arsenide from first-principles calculations: Donor compensation and doping asymmetry
摘要： We apply hybrid density functional theory calculations to identify the formation energies and thermodynamic charge transition levels of native point defects, common impurities, and shallow dopants in BAs. We find that AsB antisites, boron-related defects such as VB, BAs, and Bi-VB complexes, and antisite pairs are the dominant intrinsic defects. Native BAs is expected to exhibit p-type conduction due to the acceptor-type characteristics of VB and BAs. Among the common impurities we explored, we found that C substitutional defects and H interstitials have relatively low formation energies and are likely to contribute free holes. Interstitial hydrogen is surprisingly also found to be stable in the neutral charge state. BeB, SiAs, and GeAs are predicted to be excellent shallow acceptors with low ionization energy (<0.03 eV) and negligible compensation by other point defects considered here. On the other hand, donors such as SeAs, TeAs SiB, and GeB have a relatively large ionization energy ((cid:2)0.15 eV) and are likely to be passivated by native defects such as BAs and VB, as well as CAs, Hi, and HB. The hole and electron doping asymmetry originates from the heavy effective mass of the conduction band due to its boron orbital character, as well as from boron-related intrinsic defects that compensate donors.
关键词： dopants,donor compensation,doping asymmetry,first-principles calculations,boron arsenide,point defects
更新于2025-09-11 14:15:04
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Correlation of Coexistent Charge Transfer States in F <sub/>4</sub> TCNQ-Doped P3HT with Microstructure
摘要： Understanding the interaction between organic semiconductors (OSCs) and dopants in thin films is critical for device optimization. The proclivity of a doped OSC to form free charges is predicated on the chemical and electronic interactions that occur between dopant and host. To date, doping has been assumed to occur via one of two mechanistic pathways: an integer charge transfer (ICT) between the OSC and dopant or hybridization of the frontier orbitals of both molecules to form a partial charge transfer complex (CPX). Using a combination of spectroscopies, we demonstrate that CPX and ICT states are present simultaneously in F4TCNQ-doped P3HT films and that the nature of the charge transfer interaction is strongly dependent on the local energetic environment. Our results suggest a multiphase model, where the local charge transfer mechanism is defined by the electronic driving force, governed by local microstructure in regioregular and regiorandom P3HT.
关键词： F4TCNQ,organic semiconductors,dopants,microstructure,charge transfer,P3HT
更新于2025-09-10 09:29:36