Low temperature printable carbon cathode based perovskite solar cell was for the first time interfacial engineered with dopant free, nanorod-liked copper phthalocyanine (CuPc) to facilitate charge ...transportation. Both the CuPc and low temperature processed carbon are potentially noble metal-free and highly stable. By incorporating CuPc nanorods as hole-selective contact material, together with the printable low temperature processed carbon as cathode material, considerably high power conversion efficiency (PCE) of 16.1% was successfully obtained, which is comparable to or even a little higher than the device with state-of-the-art doped spiro-OMeTAD as HTM and noble metal Au as back electrode. Moreover, dramatically enhanced durability relative to doped-spiro-OMeTAD/Au based device was demonstrated by this newly developed device. Detailed excellent capability in accelerating charge extraction and suppressing charge recombination can be disclosed with steady state and time-resolved photoluminescence analysis and electrochemical impedance spectroscopy. To the best our knowledge, this is the highest efficiency that has been reported for PSCs based carbon counter electrode. The work presented here demonstrates an important step forwards to practical applications for PSCs, as it paves the way for developments of cost-effective, stable but still highly efficient PSCs, and offers the promise for a low-cost, mass-manufacturable technology that is compatible with current large-scale printing infrastructure.
Display omitted
•Cost-effective, noble metal-free, stable and highly efficient perovskite solar cells were demonstrated.•Low temperature (100°C) processed carbon counter electrode based perovskite solar cells was for the first time interfacial engineered with copper phathalocyanine nanorods.•Copper phathalocyanine with distinctive morphology of nanorods were found to be efficient in charge extraction and charge recombination suppression.•The best cell afforded impressive PCE of 16.1% being one of the highest efficiency for carbon counter electrode based perovskite solar cells among reported results.
Perovskite solar cells (PSCs) has skyrocketed in the past decade to an unprecedented level due to their outstanding photoelectric properties and facile processability. However, the utilization of ...expensive hole transport materials (HTMs) and the inevitable instability instigated by the deliquescent dopants represent major concerns hindering further commercialization. Here, a series of low-cost, conjugated polymers are designed and applied as dopant-free HTMs in PSCs, featuring tuned energy levels, good temperature and humidity resistivity, and excellent photoelectric properties. Further studies highlight the critical and multifaceted roles of the polymers with respect to facilitating charge separation, passivating the surface trap sites of perovskite materials, and guaranteeing long-term stability of the devices. A stabilized power conversion efficiency (PCE) of 20.3% and remarkably enhanced device longevity are achieved using the dopant-free polymer P3 with a low concentration of 5 mg/mL, qualifying the device as one of the best PSC systems constructed on the basis of dopant-free HTMs so far. In addition, the flexible PSCs based on P3 also exhibit a PCE of 16.2%. This work demonstrates a promising route toward commercially viable, stable, and efficient PSCs.
Different from traditional D−π–A sensitizers (the traditional design concept of the organic dyes is the donor−π-linker–acceptor structure), a series of organic dyes with pyridinium as acceptor have ...been synthesized in order to approach the optimal energy level composition in the TiO2–dye–iodide/triiodide system in the dye-sensitized solar cells. HOMO and LUMO energy level tuning is achieved by varying the conjugation units and the donating ability of the donor part. Detailed investigation on the relationship between the dye structure and photophysical, photoelectrochemical properties and performance of DSSCs is described. For TPA-based dyes, by substituting the 3-hexylthiophene group with a carbon–carbon double bond as π-spacer, the bathochromic shift of absorption spectra and higher current density (J sc ) are achieved. When the methoxyl and n-hexoxyl are introduced into CM301 to construct dyes CM302 and CM303, the absorption peak is red-shifted compared with that of CM301 due to the increase of the electron-donating ability. The devices fabricated with sensitizers CM302 and CM303 show higher J sc and open-circuit voltage (V oc ) than those of the device sensitized by CM301, which can be mainly attributed to the wider incident photon-to-current conversion efficiency (IPCE) response and the suppression of electron recombination between TiO2 film and electrolyte, respectively. The effects of different electron donors in DSSCs application are compared, and the results show that sensitizers with a phenothiazine (PTZ) electron-donating unit give a promising efficiency, which is even better than the TPA-based dyes. This is because the PTZ unit displayed a stronger electron-donating ability than the TPA unit (oxidation potential of 0.82 and 1.08 V vs the normal hydrogen electrode (NHE), respectively). For sensitizers CM306 and CM307, the introduction of 1,3- bis(hexyloxy)phenyl increases the donating ability of the donor part. Furthermore, the presence of long alkyl chains decreases the dye adsorption amount on the TiO2 surface, which diminishes dye aggregation and the electron recombination effectively, though, with less adsorption amount of dyes on TiO2, the device sensitized by dye CM307 obtained the best conversion efficiency of 7.1% (J sc = 13.6 mA·cm–2, V oc = 710 mV, FF = 73.6%) under AM 1.5G irradiation (100 mW·cm–2).
The phenoxazine‐based acceptor–donor–acceptor structured small‐molecule material M1 is used either as a hole‐transport material in (CH3NH3)PbI3‐perovskite‐based solar cells or as photoactive donor ...material in bulk heterojunction organic solar cells. Excellent power conversion efficiencies of 13.2% and 6.9% are achieved in these two types of photovoltaic devices, respectively.
Novel cyanine dyes, in which a tetrahydroquinoline derivative is used as an electron donor and 1‐butyl‐5‐carboxy‐3, 3‐dimethyl‐indol‐1‐ium moiety is used as an electron acceptor and anchoring group, ...were designed and synthesized for application in dye‐sensitized solar cells. The photovoltaic performance of these solar cells depends markedly on the molecular structure of the dyes in terms of the n‐hexyl chains and the methoxyl unit. Retardation of charge recombination caused by the introduction of n‐hexyl chains resulted in an increase in electron lifetime. As a consequence, an improvement of open‐circuit photovoltage (Voc) was achieved. Also, the electron injection efficiencies were improved by the introduction of methoxyl moiety, which led to a higher short‐circuit photocurrent density (Jsc). The highest average efficiency of the sensitized devices (η) was 5.6 % (Jsc=13.3 mA cm−2, Voc=606 mV, and fill factor FF=69.1 %) under 100 mW cm−2 (AM 1.5G) solar irradiation. All of these dyes have very high absorption extinction coefficients and strong absorption in a relatively narrow spectrum range (500–650 nm), so one of our organic dyes was explored as a sensitizer in co‐sensitized solar cells in combination with the other two other existing organic dyes. Interestingly, a considerably improved photovoltaic performance of 8.2 % (Jsc=20.1 mA cm−2, Voc=597 mV, and FF=68.3 %) was achieved and the device showed a panchromatic response with a high incident photon‐to‐current conversion efficiency exceeding 85 % in the range of 400–700 nm.
Sensitive dyes absorb it all: Co‐sensitization of three spectrally complementary dyes on a TiO2 film in a well‐designed sequence significantly improves the photovoltaic performance of the device, and an efficiency of 8.2 % is achieved. The devices demonstrate a panchromatic response with an incident photon‐to‐current conversion efficiency >80 % over the entire visible spectral region from 400 to 700 nm.
The overall genetic distribution and divergence of cloned genes among bread wheat varieties that have occurred during the breeding process over the past few decades in Ningxia Province, China, are ...poorly understood. Here, we report the genetic diversities of 44 important genes related to grain yield, quality, adaptation and resistance in 121 Ningxia and 86 introduced wheat cultivars and advanced lines.
The population structure indicated characteristics of genetic components of Ningxia wheat, including landraces of particular genetic resources, introduced varieties with rich genetic diversities and modern cultivars in different periods. Analysis of allele frequencies showed that the dwarfing alleles Rht-B1b at Rht-B1 and Rht-D1b at Rht-D1, 1BL/1RS translocation, Hap-1 at GW2-6B and Hap-H at Sus2-2B are very frequently present in modern Ningxia cultivars and in introduced varieties from other regions but absent in landraces. This indicates that the introduced wheat germplasm with numerous beneficial genes is vital for broadening the genetic diversity of Ningxia wheat varieties. Large population differentiation between modern cultivars and landraces has occurred in adaptation genes. Founder parents carry excellent allele combinations of important genes, with a higher number of favorable alleles than modern cultivars. Gene flow analysis showed that six founder parents have greatly contributed to breeding improvement in Ningxia Province, particularly Zhou 8425B, for yield-related genes.
Varieties introduced from other regions with rich genetic diversity and landraces with well-adapted genetic resources have been applied to improve modern cultivars. Founder parents, particularly Zhou 8425B, for yield-related genes have contributed greatly to wheat breeding improvement in Ningxia Province. These findings will greatly benefit bread wheat breeding in Ningxia Province as well as other areas with similar ecological environments.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Offshore wind power operates in a complex and harsh environment, while turbines continue to develop in the direction of large capacity and scale. Therefore, offshore wind power increasingly needs to ...reduce the overall operation and maintenance costs and improve the operation and control level of individual turbines and wind farms. Digital twin technology is intelligent, efficient and visual, and can provide intelligent services such as data analysis, fault diagnosis, performance evaluation and optimization suggestions for offshore wind power operation and maintenance. Relying on the digital twin five-dimensional model and its based prognostics health management method, a set of offshore wind power digital twin modeling system is deployed through the construction of data governance and maintenance fault recognition process. The system realizes the operation analysis and optimization of wind turbines, as well as the diagnosis and early warning of key equipment and field groups of wind turbines, which improves the management and control level of offshore wind power, improves the quality of operation and maintenance, optimizes the arrangement of offshore tasks, and reduces the cost of operation and maintenance. In the future, the system has great application prospects in predictive maintenance, quality improvement, efficient operation and maintenance of offshore wind power, providing support for the development of intelligent operation and maintenance of offshore wind power.
The success of Internet investment products such as Yu’e Bao directly relies on users' continuous participation. However, few researches have examined Internet investment products from the context of ...post-adoption. The purpose of this paper is to study continuance usage intention toward Yu’e Bao, a prevalent Internet investment product. The dual-process model (DPM) has been used in several studies of information systems continuance. We have extended the DPM by examining the impact of some critical factors that directly influence continuance usage intention including expected earnings, capital liquidity and perceived risk. We used structural equation modelling to validate the proposed model and hypotheses. We discover that perceived usefulness, perceived enjoyment, satisfaction, loyalty, habit, expected earnings and capital liquidity positively influence continuance intention. Perceived risk has a negative effect on continuance usage intention. Furthermore, the results also demonstrate that expected earnings and capital liquidity have positive impacts on users’ perceived risk. The capital liquidity has negative influence on expected earnings. The results provide important implications for research and practice in the field of information systems and finance.
In the present study, tetramethylammonium hydroquinone (HQ)/benzoquinone (BQ) were developed for use as a redox couple, with poly(3,4-ethylenedioxythiophene) (PEDOT) and multiwalled carbon nanotubes ...(MWNT) being proposed for use as counter electrode (CE) catalysts in dye-sensitized solar cells (DSSCs). Both metal-complex N719 and metal-free organic dye CM309 were employed to fabricate devices. For the devices sensitized by N719, when using PEDOT and MWNT CEs, power conversion efficiencies (PCE) of 5.2 and 4.9% were obtained, respectively, which were much higher than that of the device using the traditional Pt CE (4.7%) when HQ/BQ electrolyte was employed. However, with the HQ/BQ redox shuttle, the efficiency of the devices sensitized by N719 is much lower than that of the devices when the traditional I(-)/I3(-) based electrolyte and Pt CE were employed (7.9%). While for the CM309 sensitized solar cells, when the HQ/BQ redox shuttle was employed, PEDOT and MWNT performed much better than Pt, the DSSC using the PEDOT CE showed an efficiency of 6.2%, which was close to that of the DSSC using the traditional I(-)/I3(-) electrolyte and Pt CE (6.3%).
PDF
