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.

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.

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.

Bias-Free Solar-to-Hydrogen Conversion in a BiVO_(4)/PM6:Y6 Compact Tandem with Optically Balanced Light Absorption

The high voltage required to overcome the thermodynamic threshold and the complicated kinetics of the water splitting reaction limit the efficiency of single semiconductor-based photoelectrochemistry.A semiconductor/solar cell tandem structure has been theoretically demonstrated as a viable path to achieve an efficient direct transformation of sunlight into chemical energy.However,compact designs exhibiting the indispensable optimally balanced light absorption have not been demonstrated.In the current work,we design and implement a compact tandem providing the complementary absorption of a highly transparent BiVO_(4)photoanode and a PM6:Y6 solar cell.Such bandgap combination approaches the optimal to reach the solar-to-hydrogen(STH)conversion upper limit for tandem photoelectrochemical cells(PECs).We demonstrate that,by using a photonic multilayer structure to adequately balance sunlight absorption among both tandem materials,a 25%increase in the bias-free STH conversion can be achieved,setting a clear path to take compact tandem PECs to the theoretical limit performance.

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.

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.

Hydrogenation of CO_(2) to p-xylene over ZnZrO_(x)/hollow tubular HZSM-5 tandem catalyst

The conversion of CO_(2) into specific aromatics by modulating the morphology of zeolites is a promising strategy.HZSM-5 zeolite with hollow tubular morphology is reported.The morphology of zeolite was precisely controlled,and the acid sites on its outer surface were passivated by steam-assisted crystallization method,so that the zeolite exhibits higher aromatic selectivity than sheet HZSM-5 zeolite and greater p-xylene selectivity than chain HZSM-5 zeolite.The tandem catalyst was formed by combining hollow tubular HZSM-5 zeolites with ZnZrO_(x)metal oxides.The para-selectivity of p-xylene reached 76.2%at reaction temperature of 320℃,pressure of 3.0 MPa,and a flow rate of 2400 mL g^(-1)h^(-1)with an H_(2)/CO_(2) molar ratio of 3/1.Further research indicates that the high selectivity of p-xylene is due to the pore structure of hollow tubular HZSM-5 zeolite,which is conducive to the formation of p-xylene.Moreover,the passivation of the acid site located on the outer surface of zeolite effectively prevents the isomerization of p-xylene.The reaction mechanism of CO_(2) hydrogenation over the tandem catalyst was investigated using in-situ diffuse reflectance Fourier transform infrared spectroscopy and density functional theory.The results showed that the CO_(2) to p-xylene followed a methanol-mediated route over ZnZrO_(x)/hollow tubular HZSM-5 tandem catalysts.In addition,the catalyst showed no significant deactivation in the 100 h stability test.This present study provides an effective strategy for the design of catalysts aimed at selectively preparing aromatics through CO_(2)hydrogenation.

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.

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.

Sb_(2)Se_(3)as a bottom cell material for efficient perovskite/Sb_(2)Se_(3)tandem solar cells

Antimony selenide(Sb_(2)Se_(3))semiconducting material possesses a band gap of 1.05-1.2 eV and has been widely applied in single-junction solar cells.Based on its band gap,Sb_(2)Se_(3)can also be used as the bottom cell absorber material in tandem solar cells.More importantly,Sb_(2)Se_(3)solar cells exhibit excellent stability with nontoxic compositional elements.The band gap of organic-inorganic hybrid perovskite is tunable over a wide range.In this work,we demonstrate for the first time a perovskite/antimony selenide four-terminal tandem solar cell with a specially designed and fabricated transparent electrode for an optimized spectral response.By adjusting the thickness of the transparent electrode layer of the top cell,the wide-band-gap perovskite top solar cell achieves an efficiency of 17.88%,while the optimized antimony selenide bottom cell delivers a power conversion efficiency of 7.85%by introducing a double electron transport layer.Finally,the four-termi-nal tandem solar cell achieves an impressive efficiency exceeding 20%.This work provides a new tandem device structure and demonstrates that antimony selenide is a promising absorber material for bottom cell applications in tandem solar cells.

Four-terminal perovskite tandem solar cells

One of the primary barriers to the advancement of high-efficiency energy conversion technologies is the Shockley–Queisser limit,which imposes a fundamental efficiency constraint on single-junction solar cells.The advent of multi-junction solar cells provides a formidable alternative to this obstacle.Among these,organic-inorganic perovskite solar cells(PSCs)have captured substantial interest due to their outstanding optoelectronic properties,including tunable bandgaps and high-power conversion efficiencies,positioning them as prime candidates for multi-junction photovoltaic systems.We give a review of the latest advancements in four-terminal(4T)perovskite tandem solar cells(TSCs),emphasizing four pertinent configurations:perovskite-silicon(PVK/Si),per-ovskite-perovskite(PVK/PVK),perovskite-Cu(In,Ga)Se2(PVK/CIGS),and perovskite-organic(PVK/organic),as well as other emerging 4T perovskite TSCs.Further,it also emphasizes the advancement of semitransparent wide-bandgap PSCs for TSC applications,tackling important issues and outlining potential future directions for optimizing 4T tandem design performance.

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.

Review of all-inorganic perovskites and their tandem solar cells with crystalline silicon

In widely studied organic-inorganic hybrid perovskites,the organic component tends to volatilize and decompose under high temperatures,oxygen,and humidity,which adversely affects the performance and longevity of the associated solar cells.In contrast,all-inorganic perovskites demonstrate superior stability under these conditions and offer photoelectric properties comparable to those of their hybrid counterparts.The potential of tandem solar cells(TSCs)made from all-inorganic perovskites is especially promising.This review is the first to address recent advancements in TSCs that use all-inorganic perovskites and crystalline silicon(c-Si),both domestically and internationally.This work provides a systematic and thorough analysis of the current challenges faced by these systems and proposes rational solutions.Additionally,we elucidate the regulatory mechanisms of all-inorganic perovskites and their TSCs when combined with c-Si,summarizing the corresponding patterns.Finally,we outline future research directions for all-inorganic perovskites and their TSCs with c-Si.This work offers valuable insights and references for the continued advancement of perovskitebased TSCs.

西洋参中皂苷类成分表征和炮制导致成分转化的研究进展

西洋参富含多种药理活性物质,具有保护心血管系统、改善神经系统疾病和降血糖等多种药理作用,目前对西洋参中皂苷类成分的结构表征及炮制转化研究取得了显著进展.总结概括西洋参中皂苷类活性成分的分类和分布、现代主流分析技术以及炮制加工对皂苷类成分的转化机制,为西洋参皂苷类成分的深入挖掘和创新炮制技术等提供有效的技术支撑和指导方法,从而扩大其在医疗和保健等方面的应用.

气相色谱-串联质谱同时测定白酒中20种吡嗪类化合物

本研究采用直接进样结合气相色谱-串联质谱技术建立测定白酒中20种吡嗪类化合物的方法,并对10种香型不同品牌白酒中的吡嗪类化合物进行测定。该方法在0.01~10.00 mg/L的质量浓度范围内具有良好的线性关系,决定系数R^(2)在0.998 3~0.999 7的范围内,检出限在0.16×10^(-3)~3.25×10^(-3) mg/L范围内,不同浓度条件下的加标回收率在81.26%~113.13%之间,日内日间相对标准偏差在1.42%~4.98%之间。10种香型白酒中吡嗪类化合物的定量分析结果表明,吡嗪类化合物在酱香型白酒中含量最高,质量浓度范围为2.63~16.88 mg/L,其次是芝麻香型和兼香型。该方法与气相色谱-质谱法相比具有更高的准确度及灵敏度,适用于不同香型白酒中吡嗪类化合物的分析。

联合净化法结合高效液相色谱-串联质谱同时测定鸽蛋中5类24种兽药残留

为建立一种可同时检测鸽蛋中多类兽药残留的高通量液相色谱-串联质谱法,试验采用正己烷去脂,联合QuEChERS净化结合冷冻脂质过滤法,建立检测鸽蛋中5类24种兽药残留的高效液相色谱-串联质谱法。样品中的5类兽药(氯霉素类、磺胺类、硝基咪唑类、喹诺酮类和抗病毒类)经1.0%乙酸乙腈溶液提取,氮气吹干,冷冻过夜后,结合QuEChERS净化和正己烷去脂,采用1 mL 0.1%甲酸水-乙腈溶液(v/v,90∶10)复溶;高效液相色谱-串联质谱测定,内标法定量,采用实际样品建立方法的初步应用。结果显示:24种兽药在2.0~200 ng/mL线性关系良好(R2>0.99),该方法的定量限为2μg/kg,平均回收率为62.2%~117.1%,相对标准偏差4.3%~18.9%;实际样品检出的7种目标化合物与标准方法相比的相对标准偏差为1.34%~5.20%。研究表明,建立的检测鸽蛋中多类兽药残留的高通量液相色谱-串联质谱法省去固相萃取步骤,成本较低,灵敏高效,回收率优良、重复性稳定,适用于鸽蛋中多类兽药的快速监测分析。

4例混合谱系白血病基因部分串联重复阳性的急性白血病患儿临床特征分析

目的分析混合谱系白血病基因部分串联重复(MLL-PTD)阳性的急性白血病(AL)患儿的临床特征。方法回顾性分析2021年1月至2023年11月青岛大学附属泰安市中心医院收治的4例MLL-PTD阳性AL患儿的临床资料。结果纳入的4例MLL-PTD阳性AL患儿均为急性髓系白血病,3例为急性单核细胞白血病(M5),1例为急性早幼粒细胞白血病(M3)。女患儿3例,男患儿1例,年龄9(7.5,10)岁。初诊时高白细胞1例(33%),均无中枢系统浸润,均为高危。MLL-PTD均异常表达,波动于0.11%~8.11%;均合并多种基因突变。2个染色体异常核型,1个为t(8;21),1个为t(15;17)。3例MLL-PTD阳性M5患儿化疗后骨髓细胞学及流式均获得完全缓解,但MLL-PTD持续阳性。病例1停药4个月后骨髓复发,其父母MLL-PTD均阳性,后经非血缘脐血造血干细胞移植获得无病生存;病例2及病例3虽MLL-PTD阳性,但未复发;病例4经化疗后MLL-PTD持续阴性。该4例患儿2.5年无事件生存率及总生存率为100%。结论MLL-PTD阳性AL患儿发病率较低;正常健康人可检测到低水平的MLL-PTD;本研究MLL-PTD阳性对预后无明显影响,但仍需积累更多的病例来佐证。