Efficient PbS quantum dots tandem solar cells through compatible interconnection layer

Lead sulfide quantum dots(PbS QDs) hold unique characteristics, including bandgap tunability, solutionprocessability etc., which make them highly applicable in tandem solar cells(TSCs). In all QD TSCs, its efficiency lags much behind to their single junction counterparts due to the deficient interconnection layer(ICL) and defective subcells. To improve TSCs performance, we developed three kinds of ICL structures based on 1.34 and 0.96 e V PbS QDs subcells. The control, 1,2-ethanedithiol capped PbS QDs(PbS-EDT)/Au/tin dioxide(SnO_(2))/zinc oxide(Zn O), utilized SnO_(2) layer to obtain high surface compactness.However, its energy level mismatch causes incomplete recombination. Bypassing it, the second ICL(PbS-EDT/Au/Zn O) removed SnO_(2) and boosted the power conversion efficiency(PCE) from 5.75% to 8.69%. In the third ICL(PbS-EDT/poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine](PTAA)/Au/Zn O), a thin layer of PTAA can effectively fill fissures on the surface of PbS-EDT and also protect the front cells from solvent penetration. This TSC obtained a PCE of 9.49% with an open circuit voltage of 0.91 V, a short circuit current density of 15.47 m A/cm~2, and a fill factor of 67.7%. To the best of our knowledge, this was the highest PCE achieved by all PbS QD TSCs reported to date. These TSCs maintained stable performance for a long working time under ambient conditions.

Experimental Study on Vortex-Induced Vibration of Rough Risers Coupling with Interference Effect in Tandem Arrangement

In order to study the response law of vortex-induced vibration(VIV)of marine risers under the combined action of roughness and interference effects,and to reveal the coupling mechanism of roughness and interference effects on the riser,a VIV experiment of rough risers in tandem arrangement was conducted in a wave−current combined flume.The experiment characterized the risers’roughness by arranging different specifications of attachments on the surface of the risers.Three rough risers with different roughness and smooth risers were arranged in tandem arrangement,with the rough risers arranged downstream.The experimental results indicate that the suppression of the attachments on the downstream risers’vibration are more significant both in the CF and IL directions as the reduced velocity increases.For the downstream riser,the amplitude response of rough riser is more significantly weakened compared with the smooth one at high reduced velocity.For the upstream risers,changes in the roughness and spacing ratio have an impact on their‘lock-in’region.When the roughness of downstream risers is relatively large(0.1300)and the spacing between risers is small(S/D=4.0),the reduced velocity range of‘lock-in’region in the CF direction of upstream risers is obviously expanded,and the displacement in the‘lock-in’region is severer.

Surface repair of wide-bandgap perovskites for high-performance all-perovskite tandem solar cells

Wide-bandgap(WBG)perovskite solar cells(PSCs)play a fundamental role in perovskite-based tandem solar cells.However,the efficiency of WBG PSCs is limited by significant open-circuit voltage losses,which are primarily caused by surface defects.In this study,we present a novel method for modifying surfaces using the multifunctional S-ethylisothiourea hydrobromide(SEBr),which can passivate both Pb^(-1)and FA^(-1)terminated surfaces,Moreover,the SEBr upshifted the Fermi level at the perovskite interface,thereby promoting carrier collection.This proposed method was effective for both 1.67 and 1.77 eV WBG PSCs,achieving power conversion efficiencies(PCEs)of 22.47%and 19.90%,respectively,with V_(OC)values of 1.28 and 1.33 V,along with improved film and device stability.With this advancement,we were able to fabricate monolithic all-perovskite tandem solar cells with a champion PCE of 27.10%,This research offers valuable insights for passivating the surface trap states of WBG perovskite through rational multifunctional molecular engineering.

Electrochemically Deposited CZTSSe Thin Films for Monolithic Perovskite Tandem Solar Cells with Efficiencies Over 17%

In spite of the high potential economic feasibility of the tandem solar cells consisting of the halide perovskite and the kesterite Cu2ZnSn(S,Se)4(CZTSSe),they have rarely been demonstrated due to the difficulty in implementing solution-processed perovskite top cell on the rough surface of the bottom cells.Here,we firstly demonstrate an efficient monolithic two-terminal perovskite/CZTSSe tandem solar cell by significantly reducing the surface roughness of the electrochemically deposited CZTSSe bottom cell.The surface roughness(R_(rms))of the CZTSSe thin film could be reduced from 424 to 86 nm by using the potentiostatic mode rather than using the conventional galvanostatic mode,which can be further reduced to 22 nm after the subsequent ion-milling process.The perovskite top cell with a bandgap of 1.65 eV could be prepared using a solution process on the flattened CZTSSe bottom cell,resulting in the efficient perovskite/CZTSSe tandem solar cells.After the current matching between two subcells involving the thickness control of the perovskite layer,the best performing tandem device exhibited a high conversion efficiency of 17.5%without the hysteresis effect.

Surface-functionalized hole-selective monolayer for high efficiency single-junction wide-bandgap and monolithic tandem perovskite solar cells

Carbazole moiety-based 2PACz([2-(9H-carbazol-9-yl)ethyl]phosphonic acid)self-assembled monolayers(SAMs)are excellent hole-selective contact(HSC)materials with abilities to excel the charge-transferdynamics of perovskite solar cells(PSCs).Herein,we report a facile but powerful method to functionalize the surface of 2PACz-SAM,by which reproducible,highly stable,high-efficiency wide-bandgap PSCs can be obtained.The 2PACz surface treatment with various donor number solvents improves assembly of 2PACz-SAM and leave residual surface-bound solvent molecules on 2PACz-SAM,which increases perovskite grain size,retards halide segregation,and accelerates hole extraction.The surface functionalization achieves a high power conversion efficiency(PCE)of 17.62%for a single-junction wide-bandgap(~1.77 e V)PSC.We also demonstrate a monolithic all-perovskite tandem solar cell using surfaceengineered HSC,showing high PCE of 24.66%with large open-circuit voltage of 2.008 V and high fillfactor of 81.45%.Our results suggest this simple approach can further improve the tandem device,when coupled with a high-performance narrow-bandgap sub-cell.

Non-destructive buffer enabling near-infrared-transparent inverted inorganic perovskite solar cells toward 1400 h light-soaking stable perovskite/Cu(In,Ga)Se_(2) tandem solar cells

Near-infrared(NIR)transparent inverted all-inorganic perovskite solar cells(PSCs)are excellent top cell candidates in tandem applications.An essential challenge is the replacement of metal contacts with transparent conductive oxide(TCO)electrodes,which requires the introduction of a buffer layer to prevent sputtering damage.In this study,we show that the conventional buffers(i.e.,small organic molecules and atomic layer deposited metal oxides)used for organic-inorganic hybrid perovskites are not applicable to all-inorganic perovskites,due to non-uniform coverage of the vulnerable layers underneath,deterioration upon ion bombardment and moisture induced perovskite phase transition,A thin film of metal oxide nanoparticles by the spin-coating method serves as a non-destructive buffer layer for inorganic PSCs.All-inorganic inverted near-infrared-transparent PSCs deliver a PCE of 17.46%and an average transmittance of 73.7%between 780 and 1200 nm.In combination with an 18.56%Cu(In,Ga)Se_(2) bottom cell,we further demonstrate the first all-inorganic perovskite/CIGS 4-T tandem solar cell with a PCE of 24.75%,which exhibits excellent illumination stability by maintaining 86.7%of its initial efficiency after 1400 h.The non-destructive buffer lays the foundation for efficient and stable NIR-transparent inverted inorganic perovskite solar cells and perovskite-based tandems.

Efficient Monolithic Perovskite/Silicon Tandem Photovoltaics

Tunable bandgaps make halide perovskites promising candidates for developing tandem solar cells(TSCs),a strategy to break the radiative limit of 33.7%for single-junction solar cells.Combining perovskites with market-dominant crystalline silicon(c-Si)is particularly attractive;simple estimates based on the bandgap matching indicate that the efficiency limit in such tandem device is as high as 46%.However,state-of-the-art perovskite/c-Si TSCs only achieve an efficiency of~32.5%,implying significant challenges and also rich opportunities.In this review,we start with the operating mechanism and efficiency limit of TSCs,followed by systematical discussions on wide-bandgap perovskite front cells,interface selective contacts,and electrical interconnection layer,as well as photon management for highly efficient perovskite/c-Si TSCs.We highlight the challenges in this field and provide our understanding of future research directions toward highly efficient and stable large-scale wide-bandgap perovskite front cells for the commercialization of perovskite/c-Si TSCs.

Textured Perovskite/Silicon Tandem Solar Cells Achieving Over 30% Efficiency Promoted by 4-Fluorobenzylamine Hydroiodide

Monolithic textured perovskite/silicon tandem solar cells(TSCs)are expected to achieve maximum light capture at the lowest cost,potentially exhibiting the best power conversion efficiency.However,it is challenging to fabricate high-quality perovskite films and preferred crystal orientation on commercially textured silicon substrates with micrometersize pyramids.Here,we introduced a bulky organic molecule(4-fluorobenzylamine hydroiodide(F-PMAI))as a perovskite additive.It is found that F-PMAI can retard the crystallization process of perovskite film through hydrogen bond interaction between F^(−)and FA^(+)and reduce(111)facet surface energy due to enhanced adsorption energy of F-PMAI on the(111)facet.Besides,the bulky molecular is extruded to the bottom and top of perovskite film after crystal growth,which can passivate interface defects through strong interaction between F-PMA+and undercoordinated Pb^(2+)/I^(−).As a result,the additive facilitates the formation of large perovskite grains and(111)preferred orientation with a reduced trap-state density,thereby promoting charge carrier transportation,and enhancing device performance and stability.The perovskite/silicon TSCs achieved a champion efficiency of 30.05%based on a silicon thin film tunneling junction.In addition,the devices exhibit excellent longterm thermal and light stability without encapsulation.This work provides an effective strategy for achieving efficient and stable TSCs.

Defect Engineering in Earth-Abundant Cu_(2)ZnSnSe_(4) Absorber Using Efficient Alkali Doping for Flexible and Tandem Solar Cell Applications

To demonstrate flexible and tandem device applications,a low-temperature Cu_(2)ZnSnSe_(4)(CZTSe)deposition process,combined with efficient alkali doping,was developed.First,high-quality CZTSe films were grown at 480℃by a single co-evaporation,which is applicable to polyimide(PI)substrate.Because of the alkali-free substrate,Na and K alkali doping were systematically studied and optimized to precisely control the alkali distribution in CZTSe.The bulk defect density was significantly reduced by suppression of deep acceptor states after the(NaF+KF)PDTs.Through the low-temperature deposition with(NaF+KF)PDTs,the CZTSe device on glass yields the best efficiency of 8.1%with an improved Voc deficit of 646 mV.The developed deposition technologies have been applied to PI.For the first time,we report the highest efficiency of 6.92%for flexible CZTSe solar cells on PI.Additionally,CZTSe devices were utilized as bottom cells to fabricate four-terminal CZTSe/perovskite tandem cells because of a low bandgap of CZTSe(~1.0 eV)so that the tandem cell yielded an efficiency of 20%.The obtained results show that CZTSe solar cells prepared by a low-temperature process with in-situ alkali doping can be utilized for flexible thin-film solar cells as well as tandem device applications.

DNA Tandem Repeats as Iterable Objects to Count Cell Divisions: A Computational Model

Cell lineages of nematodes are completely known: the adult male of Caenorhabditis elegans contains 1031 somatic cells, the hermaphrodite 959, not one more, not one less;cell divisions are strictly deterministic (as in the great majority of invertebrates) but so far nothing is known about the mechanism used by cells to count precise numbers of divisions. In vertebrates, each species has its invariable deterministic numbers of somites, vertebrae, fingers, and teeth: counting the number of iterations is a widespread process in living beings;nonetheless, it remains an unanswered question and a great challenge in cell biology. This paper introduces a computational model to investigate the possible role of satellite DNA in counting cell divisions, showing how cells may operate under Boolean logic algebra. Satellite DNA, made up of repeated monomers and subject to high epigenetic methylation rates, is very similar to iterable sequences used in programming: just like in the “iteration protocol” of algorithms, the epigenetic machinery may run over linear tandem repeats (that hold cell-fate data), read and orderly mark one monomer per cell-cycle (cytosine methylation), keep track and transmit marks to descendant cells, sending information to cell-cycle regulators.

Research on the Upper Limit of Accuracy for Predicting Theoretical Tandem Mass Spectrometry

In recent years, numerous theoretical tandem mass spectrometry prediction methods have been proposed, yet a systematic study and evaluation of their theoretical accuracy limits have not been conducted. If the accuracy of current methods approaches this limit, further exploration of new prediction techniques may become redundant. Conversely, a need for more precise prediction methods or models may be indicated. In this study, we have experimentally analyzed the limits of accuracy at different numbers of ions and parameters using repeated spectral pairs and integrating various similarity metrics. Results show significant achievements in accuracy for backbone ion methods with room for improvement. In contrast, full-spectrum prediction methods exhibit greater potential relative to the theoretical accuracy limit. Additionally, findings highlight the significant impact of normalized collision energy and instrument type on prediction accuracy, underscoring the importance of considering these factors in future theoretical tandem mass spectrometry predictions.

GEDI与Tandem-X DEM估测密林林下地形性能评价

针对密林情况下,GEDI数据与现有的Tandem-X DEM数字地面模型估测林下地形精度没有进行整体评价问题,拟以密林情况作为主要分析场景,通过提取GEDI L2A数据产品对应光斑的经纬度、林下地形信息与数据质量筛选参数,开展数据质量筛选,用以估测基于GEDI数据的林下地形数据,与Tandem-X DEM数据估测密林情况下研究区林下地形开展比较,并进一步探究冠层高度、森林覆盖度与植被类型对估测精度的影响。GEDI与Tandem-X DEM的R~2分别为0.99和0.98,GEDI估测林下地形结果的RMSE、Average与STD分别6.49、-1.92、4.42 m, Tandem-X DEM估测林下地形结果的RMSE、Average与STD分别为18.15、14.63、7.35 m。GEDI数据在混交林和稀疏草原情况下RMSE与Average分别变化8.05 m和6.04 m, Tandem-X DEM数据在常绿针叶林与农田/天然植被情况下,RMSE与Average变化幅度为21.63、26.43 m。实验结果表明,GEDI与Tandem-X DEM数据与机载验证数据存在强相关性,且GEDI相对Tandem-X DEM数据表现出更优的评价标准;地表植被类型相对冠层高度和植被覆盖度会对两数据估测林下地形精度产生更大的影响。

Tandem Mass Tag-based proteomics analysis reveals the vital role of inflammation in traumatic brain injury in a mouse model

Proteomics is a powerful tool that can be used to elucidate the underlying mechanisms of diseases and identify new biomarkers.Therefore,it may also be helpful for understanding the detailed pathological mechanism of traumatic brain injury(TBI).In this study,we performed Tandem Mass Tag-based quantitative analysis of cortical proteome profiles in a mouse model of TBI.Our results showed that there were 302 differentially expressed proteins in TBI mice compared with normal mice 7 days after injury.Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses showed that these differentially expressed proteins were predominantly involved in inflammatory responses,including complement and coagulation cascades,as well as chemokine signaling pathways.Subsequent transcription factor analysis revealed that the inflammation-related transcription factors NF-κB1,RelA,IRF1,STAT1,and Spi1 play pivotal roles in the secondary injury that occurs after TBI,which further corroborates the functional enrichment for inflammatory factors.Our results suggest that inflammation-related proteins and inflammatory responses are promising targets for the treatment of TBI.

4‑Terminal Inorganic Perovskite/Organic Tandem Solar Cells Offer 22%Efficiency

After fast developing of single-junction perovskite solar cells and organic solar cells in the past 10 years,it is becoming harder and harder to improve their power conversion efficiencies.Tandem solar cells are receiving more and more attention because they have much higher theoretical efficiency than single-junction solar cells.Good device performance has been achieved for perovskite/silicon and perovskite/perovskite tandem solar cells,including 2-terminal and 4-terminal structures.However,very few studies have been done about 4-terminal inorganic perovskite/organic tandem solar cells.In this work,semi-transparent inorganic perovskite solar cells and organic solar cells are used to fabricate 4-terminal inorganic perovskite/organic tandem solar cells,achieving a power conversion efficiency of 21.25%for the tandem cells with spin-coated perovskite layer.By using drop-coating instead of spin-coating to make the inorganic perovskite films,4-terminal tandem cells with an efficiency of 22.34%are made.The efficiency is higher than the reported 2-terminal and 4-terminal inorganic perovskite/organic tandem solar cells.In addition,equivalent 2-terminal tandem solar cells were fabricated by connecting the sub-cells in series.The stability of organic solar cells under continuous illumination is improved by using semi-transparent perovskite solar cells as filter.

Tandem catalysis for enhanced CO oxidation over the Bi-Au-SiO_(2)interface

Bimetallic catalysts typically exploit unique synergetic effects between two metal species to achieve their catalytic effect.Understanding the mechanism of CO oxidation using hybrid heterogeneous catalysts is important for effective catalyst design and environmental protection.Herein,we report a Bi-Au/SiO_(2)tandem bimetallic catalyst for the oxidation of CO over the Au/SiO_(2)surface,which was monitored using near-ambient-pressure X-ray photoelectron spectroscopy.The Au-decorated SiO_(2)catalyst exhibited scarce activity in the CO oxidation reaction;however,the introduction of Bi to the Au/SiO_(2)system promoted the catalytic activity.The mechanism is thought to involve the dissociation O_(2)molecules in the presence of Bi,which results in spillover of the O species to adjacent Au atoms,thereby forming Au^(δ+).Further CO adsorption,followed by thermal treatment,facilitated the oxidation of CO at the Au-Bi interface,resulting in a reversible reversion to the neutral Au valence state.Our work provides insight into the mechanism of CO oxidation on tandem surfaces and will facilitate the rational design of other Au-based catalysts.

Recent progress on efficient perovskite/organic tandem solar cells

The concept of tandem solar cells(TSCs) is an effective way to substantially further improve the efficiency of solar cells. The excellent optoelectronic properties and bandgap tunability of perovskites make them promising for constructing efficient TSCs. Currently, TSCs based on perovskite have been extensively studied. Besides, the performance of organic solar cells has been greatly improved recently due to the wider and more efficient spectral utilization. Accordingly, research on perovskite/organic TSCs has garnered significant attention. It has potential application advantages in emerging fields such as wearable devices by virtue of flexibility. In addition, orthogonal solvents can be adopted to realize the separate preparation of subcells with the solution method, which greatly reduces fabrication complexity;moreover, fabrication with less equipment significantly cuts down the device cost. Meanwhile, organics with more adjustability on the optoelectronic properties provide more tuning strategies for high-performance perovskite/organic TSCs. However, comprehensive and timely reviews on the perovskite/organic TSCs are deficient. Therefore, we expect to accomplish a review on this innovative TSCs to facilitate researchers with a deeper understanding of perovskite/organic TSCs. Herein, we firstly review the significant progress of perovskite and organic solar cells. Then, current achievements of perovskite/organic TSCs are summarized and introduced with a particular focus on the device structure design. Finally, we discuss existential challenges and propose effective strategies for future engineering.

Growth of tandem long-mat rice seedlings using controlled release fertilizers:Mechanical transplantation can be more economical and high yielding

The traditional soil-based rice seedling production methods for mechanical transplanting are resource-intensive,time consuming and laborious.The improvement and optimization of nutrient management in soil-less nursery raising methods like tandem long-mat seedlings(TLMS)are necessary for the resource-efficient cultivation of rice.In the present study,a controlled-release fertilizer(CRF)-polymer-coated compound fertilizer with 3 months release period(PCCF-3M)was applied as seedling fertilizer(SF),and five different dosages of SF(SF-0,SF-10,SF-20,SF-30,and SF-40)were compared with an organic substrate as the control(CK).Among all SF treatments,the best results were obtained with the application of 20 g/tray of SF(SF-20),as the seedling quality and machine transplanting quality were comparable to those of CK.In contrast,the lower dosages(SF-0 and SF-10)resulted in low nitrogen content and reduced shoot growth,while the higher dosages(SF-30 and SF-40)resulted in toxicity(increased malondialdehyde accumulation)and inhibited the root growth.Similarly,SF-20 increased panicle number(5.6-7.0%)and yield(4.3-5.3%)compared with CK,which might be related to the remaining SF entangled in the roots supporting the tiller growth of rice seedlings in the field.Moreover,SF-20 reduced the seedling block weight(53.1%)and cost of seedling production(23.5%)but increased the gross margin,indicating that it was easy to handle and economical.Taken together,our results indicate that SF-20 is a cost-effective way to promote the growth and transplanting efficiency of rice seedlings.To our knowledge,this study is the first to determine the optimum dosage of CRF for the soil-less production of rice seedlings.

Efficiency-loss analysis of monolithic perovskite/silicon tandem solar cells by identifying the patterns of a dual two-diode model’s current-voltage curves

In this work,we developed a simple and direct circuit model with a dual two-diode model that can be solved by a SPICE numerical simulation to comprehensively describe the monolithic perovskite/crystalline silicon(PVS/c-Si)tandem solar cells.We are able to reveal the effects of different efficiency-loss mechanisms based on the illuminated current density-voltage(J-V),semi-log dark J-V,and local ideality factor(m-V)curves.The effects of the individual efficiency-loss mechanism on the tandem cell’s efficiency are discussed,including the exp(V/VT)and exp(V/2VT)recombination,the whole cell’s and subcell’s shunts,and the Ohmic-contact or Schottky-contact of the intermediate junction.We can also fit a practical J-V curve and find a specific group of parameters by the trial-and-error method.Although the fitted parameters are not a unique solution,they are valuable clues for identifying the efficiency loss with the aid of the cell’s structure and experimental processes.This method can also serve as an open platform for analyzing other tandem solar cells by substituting the corresponding circuit models.In summary,we developed a simple and effective methodology to diagnose the efficiency-loss source of a monolithic PVS/c-Si tandem cell,which is helpful to researchers who wish to adopt the proper approaches to improve their solar cells.

基于TerraSAR-X/TanDEM-X数据的森林高度反演算法研究

基于RVoG模型,对传统三阶段算法及其改进算法进行研究,以云南省西双版纳州勐腊县为研究区,以TerraSAR-X/TanDEM-X数据为数据源进行森林高度反演算法研究,并结合野外实测数据进行结果验证。结果表明,三阶段改进算法对森林高度反演精度优于传统三阶段算法。三阶段改进算法对天然林高度反演精度较高;三阶段算法对橡胶林高度反演精度较高。

双基线TanDEM-X InSAR数据的森林高度反演

森林高度是进行森林资源管理的重要基础数据,通常使用RVoG模型并结合PolInSAR技术获取,然而目前的PolInSAR数据均通过重轨飞行方式采集,不利于大范围、高精度森林高度测绘。TanDEM-X数据无时间去相干与大气干扰,为森林高度测绘提供了合适的数据来源。但TanDEM-X InSAR数据主要为单极化模式,由于观测信息不足,不满足RVoG模型的解算要求。因此,文中利用双基线TanDEM-X InSAR数据反演森林高度。该方法考虑地形影响采用S-RVoG模型反演森林高度,首先仅使用S-RVoG模型相干性信息建立关系,并通过双基线下相位信息之间的关系进行约束。反演森林高度依赖于消光系数的选择,依据模型相干性对森林高度的敏感性进行分析,并利用LiDAR数据作为先验信息进行消光系数的选择。为了验证本方法,采用了瑞典与西班牙实验区数据进行双基线森林高度反演并利用实验区存在的LiDAR树高数据验证方法的精度,两实验区精度分别为1.86 m与2.43 m。