- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Making benzotrithiophene derivatives dopant-free for perovskite solar cells: Step-saving installation of π-spacers by a direct C–H arylation strategy
摘要： Previously, benzotrithiophene (BTT)-based hole-transporting materials (HTMs) had to be doped with three chemical agents for high-efficiency perovskite solar cells (PSC). This work describes significant progress by which the first dopant-free BTT core-based HTM (YKP03) with EDOT spacers was readily accessed by step-saving direct C–H arylation. PSCs with dopant-free YKP03 showed promising efficiencies of up to 16.15% with potential long-term storage stability.
关键词： direct C–H arylation,benzotrithiophene,dopant-free,perovskite solar cells,hole-transporting materials
更新于2025-09-16 10:30:52
-
Electrostatically Doped Silicon Nanowire Arrays for Multispectral Photodetectors
摘要： Nanowires have promising applications as photodetectors with superior ability to tune absorption with morphology. Despite their high optical absorption, the quantum efficiencies of these nanowire photodetectors remain low due to difficulties in fabricating a shallow junction using traditional doping methods. As an alternative, we report non-conventional radial heterojunction photodiodes obtained by conformal coating of indium oxide layer on silicon nanowire arrays. The indium oxide layer has a high work function which induces a strong inversion in the silicon nanowire and creates a virtual p-n junction. The resulting nanowire photodetectors show efficient carrier separation and collection leading to an improvement of quantum efficiency up to 0.2. In addition, by controlling the nanowire radii, the spectral response of the In2O3/Si nanowire photodetectors are tuned over several visible light wavelengths, creating a multispectral detector. Our approach is promising for the development of highly-efficient wavelength selective photodetectors.
关键词： electrostatic doping,nanowire photodetectors,multispectral,photosensors,silicon nanowire,dopant-free,radial junction
更新于2025-09-16 10:30:52
-
Solvent Engineering of a Dopant-Free Spiro-OMeTAD Hole-Transport Layer for cm-Scale Perovskite Solar Cells having High Efficiency and Thermal Stability
摘要： High efficiency and environmental stability are mandatory performance requirements for commercialization of perovskite solar cells (PSCs). Herein, efficient cm-scale PSCs with improved stability were achieved by incorporating an additive-free 2,2’,7,7’-tetrakis[N,N-di(p-methoxyphenyl)amino]-9,9’-spirobifluorene (spiro-OMeTAD) hole transporting material (HTM) through simply substituting the usual chlorobenzene solvent with pentachloroethane (PC). A stabilized power conversion efficiency of 16.1% under simulated AM 1.5G 1-sun illumination with an aperture of 1.00 cm2 was achieved for PSCs using an additive-free spiro-OMeTAD layer cast from PC. X-ray analysis suggested chlorine radicals from pentachloroethane transferred partially to spiro-OMeTAD and retain in the HTM film, resulting of conductivity improvement. Moreover, unencapsulated PSCs having cm-scale active area cast from PC retained >70% of their initial PCE after ageing at 80 °C for 500 h, in contrast with less than 20% retention for control devices. Morphological and X-ray analysis of the aged cells revealed that the perovskite and HTM layers remain almost unchanged in the cells with spiro-OMeTAD layer cast from PC whereas serious degradation occurred in the control cells. This study not only reveals the decomposition mechanism of PSCs in the presence of HTM-additives, but also opens up a broad range of organic semiconductors for radical doping.
关键词： stability,spiro-OMeTAD,perovskite solar cell,hole transporting materials,dopant-free,radical,pentachloroethane
更新于2025-09-16 10:30:52
-
Influence of post deposition fabrication steps and quantitative estimation of band diagram of Si/MoOX heterojunction for carrier selective solar cells
摘要： Heterojunction of molybdenum oxide with silicon is used as an effective hole collector in Si based carrier selective solar cells. Although the deposition of MoOX on Si is a low temperature process, the subsequent processes involved in the fabrication of the solar cell can impact the hole collection efficiency of Si/MoOX junction. In this manuscript we address the influence of post-deposition fabrication processes the subsequent processes involved in the fabrication of the solar cell can impact the hole collection efficiency of Si/MoOX junction. In this work we have found that the necessary annealing and sputtering steps have a degrading impact on the heterojunction. The underlying reasons are identified and widely described. Furthermore, to gain insight into the unique transport mechanism of heterojunction, a quantitative band diagram is obtained based on the empirical data (electron spectroscopy, optical and electrical measurements). The workfunction of thermally evaporated MoOX is found to be strongly substrate dependent and the electron affinity is deduced and measured to be 5.09 eV. The doping of MoOX films due to oxygen vacancies is found to be non-uniform as the oxygen content of the film decreases rapidly, from MoOX surface to Si/MoOX interface. Lastly, we report Si/MoOX heterojunction solar cells with high short circuit current of 33.9 mA/cm2, an open circuit voltage (VOC) of 585 mV, and an efficiency of 12.8%.
关键词： Heterojunction,Dopant-free solar cells,Molybdenum oxide
更新于2025-09-12 10:27:22
-
Dopant-free molecular hole transport material that mediates a 20% power conversion efficiency in a perovskite solar cell
摘要： Organic molecular hole-transport materials (HTMs) are appealing for the scalable manufacture of perovskite solar cells (PSCs) because they are easier to reproducibly prepare in high purity than polymeric and inorganic HTMs. There is also a need to construct PSCs without dopants and additives to avoid formidable engineering and stability issues. We report here a power conversion efficiency (PCE) of 20.6% with a molecular HTM in an inverted (p–i–n) PSC without any dopants or interlayers. This new benchmark was made possible by the discovery that, upon annealing, a spiro-based dopant-free HTM (denoted DFH) containing redox-active triphenyl amine (TPA) units undergoes preferential molecular organization normal to the substrate. This structural order, governed by the strong intermolecular interactions of the DFH dioxane groups, affords high intrinsic hole mobility (1 (cid:2) 10(cid:3)3 cm2 V(cid:3)1 s(cid:3)1). Annealing films of DFH also enables the growth of large perovskite grains (up to 2 lm) that minimize charge recombination in the PSC. DFH can also be isolated at a fraction of the cost of any other organic HTM.
关键词： molecular organization,dopant-free,perovskite solar cells,hole-transport materials,power conversion efficiency
更新于2025-09-12 10:27:22
-
Fluorination of pyrene-based organic semiconductors enhances the performance of light emitting diodes and halide perovskite solar cells
摘要： In this work, a fluorinated pyrene-based organic semiconductor (L-F) has been designed and synthesized starting from a low-cost pyrene core functionalized with triphenilamine substituents at 1,3,6,8 positions (L-H), obtained via Suzuki coupling reactions. Its performance when used as green emitter in organic light emitting diodes (OLEDs) or as dopant-free hole-transporting material (HTM) in halide perovskite solar cells (PSCs) is higher than the L-H counterpart, in spite of its lower bulk hole-mobility (7.0 x 10-6 cm2/Vs) with respect to L-H (1.9 x 10-4 cm2/Vs). In fact, the OLED devices based on L-F active layer showed excellent green emission (brightness and current efficiency were1759.8 cd/m2 and 3.7 cd/A, respectively) at a 4.5 V turn-on voltage. When the molecules were employed as a dopant-free HTM in PSCs, L-F led to a power conversion efficiency (PCE) and open circuit voltage (Voc) of 5.9 % and 1.07 V, respectively, thus outperforming those of corresponding devices based on L-H (PCE = 5.0% and Voc = 0.87 V) under similar experimental conditions (AM 1.5G and 100 mW cm2). We attribute the enhancements of L-F-based optoelectronic devices (OLEDs and PSCs) to the observed better quality of theL-F films. The promising performance of L-F indicates that fluorination of small molecules can be an effective strategy to achieve low-cost and high-performing materials for energy harvesting and display-based organic electronic devices.
关键词： pyrene,perovskite solar cells,hole transporting material,triphenylamine,fluorination,dopant-free,organic light emitting diodes
更新于2025-09-12 10:27:22
-
Hard mask processing of 20% efficiency back-contacted silicon solar cells with dopant-free heterojunctions
摘要： Single junction crystalline silicon (c-Si) solar cells featuring a conventionally doped interdigitated back contact heterojunction (IBC-SHJ) structure has approached a record efficiency of 26.6%, which is very close to the practical limit. However, integrating the interdigital p- and n-type amorphous silicon (a-Si:H) layers on the rear surface of Si substrate is of such complexity, posing problem of heavy dependences on expensive manufacturing techniques including plasma-enhanced chemical vapor deposition and photolithography. Its commercial potential is thus always being questioned, and to seek an alternative fabrication procedure, which adapts to cost-effective deposition parallel with simple patterning characteristics, has been a primary research target of related subjects. Here, we demonstrated 20.1% efficiency dopant-free IBC-SHJ solar cells by combining evaporated carrier-selective materials (MoOx and LiFx) and two-steps hard masks alignments, delivering substantial simplifications in the architecture and fabrication procedures. We investigated the effect of intrinsic a-Si:H films with different thicknesses on the passivation and contact resistance for both a-Si:H/MoOx and a-Si:H/LiFx contacts, showing 4 nm a-Si:H is better for high efficiency IBC-SHJ solar cells. We also found that the position of the metal target (electrode definition step) and isolation in between the busbar and the Si substrate are highly relevant to leakage and recombination and have great impact on the device performance. The dopant-free IBC-SHJ solar cells demonstrated here manifest enough confidence in our hard mask based fabrication procedure, with great potential for high performance-to-cost ratio in future.
关键词： solar cells,dopant-free,interdigitated back contact,silicon,carrier-selective,contacts,heterojunction
更新于2025-09-12 10:27:22
-
Electro-active nanofibers of a tetrathiafulvalene derivative with amide hydrogen bonds as a dopant-free hole transport material for perovskite solar cells
摘要： A tetrathiafulvalene derivative containing two amide units for intermolecular hydrogen bonds (Bis-amide-TTF) was found to form supramolecular assemblies, in which intermolecular TTF cores were stacked with each other. The electrical conductivity of Bis-amide-TTF-based film was 1.28 × 10?5 S cm?1, which was greater than that of spiro-OMeTAD doped with lithium salt and t-butylpyridine (8.37 × 10?6 S cm?1). Bis-amide-TTF was applied as a hole transport material (HTM) for perovskite solar cells (PSCs). The Bis-amide-TTF film has a deeper HOMO level than that of spiro-OMeTAD, leading to an increased open-circuit voltage of the PSCs. The power conversion efficiency of 14.5% with a short-circuit current density (Jsc) of 19.8 mA cm?2, an open-circuit voltage (Voc) of 1.11 V, and a fill factor (FF) of 66% was achieved for PSCs fabricated with the dopant-free Bis-amide-TTF-based HTM, which was comparable to that obtained with spiro-OMeTAD with the dopants (15.5%).
关键词： Hole transport materials,Nanofibers,Hydrogen bonds,Tetrathiafulvalene,Dopant free,Perovskite solar cells
更新于2025-09-12 10:27:22
-
Impact of A‐D‐A Structured Dithienosilole and Phenoxazine based Small Molecular Material for Bulk Heterojunction and Dopant‐free Perovskite Solar Cells
摘要： In this communication, we have designed and synthesized a novel acceptor-donor-acceptor (A-D-A) structured small molecule Si-PO-2CN based on dithienosilole (DTS) as building block flanked by electron-rich Phenoxazine (POZ) units terminated with dicyanovinylene which showed unique electrochemical and photo-physical properties. Si-PO-2CN has been successfully employed in perovskite solar cells (PSCs) as well as in bulk hetero-junction organic solar cells (OSCs). The PSCs fabricated with dopant free Si-PO-2CN as hole-transport material (HTM) exhibited a power conversion efficiency (PCE) of 14.1% (active area 1.02 cm2). Additionally, PCE of 5.6% has been achieved for OSCs using Si-PO-2CN as p-type donor material when blended with PC71BM acceptor. The versatile application of Si-PO-2CN provides path way for further implementation of DTS based building blocks in solar cells for designing new molecules.
关键词： A-D-A structured,dopant-free perovskite solar cells,bulk heterojunction,phenoxazine,small molecular material,dithienosilole
更新于2025-09-11 14:15:04
-
High‐Performance Inverted Planar Perovskite Solar Cells Enhanced by Thickness Tuning of New Dopant‐Free Hole Transporting Layer
摘要： A new hole transporting material (HTM) named DMZ is synthesized and employed as a dopant-free HTM in inverted planar perovskite solar cells (PSCs). Systematic studies demonstrate that the thickness of the hole transporting layer can effectively enhance the morphology and crystallinity of the perovskite layer, leading to low series resistance and less defects in the crystal. As a result, the champion power conversion efficiency (PCE) of 18.61% with JSC = 22.62 mA cm?2, VOC = 1.02 V, and FF = 81.05% (an average one is 17.62%) is achieved with a thickness of ≈13 nm of DMZ (2 mg mL?1) under standard global AM 1.5 illumination, which is ≈1.5 times higher than that of devices based on poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonic acid) (PEDOT:PSS). More importantly, the devices based on DMZ exhibit a much better stability (90% of maximum PCE retained after more than 556 h in air (relative humidity ≈ 45%–50%) without any encapsulation) than that of devices based on PEDOT:PSS (only 36% of initial PCE retained after 77 h in same conditions). Therefore, the cost-effective and facile material named DMZ offers an appealing alternative to PEDOT:PSS or polytriarylamine for highly efficient and stable inverted planar PSCs.
关键词： inverted planar structure,perovskite solar cells,dopant-free,hole transporting materials
更新于2025-09-11 14:15:04