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961.
Indranil Mondal Hyunhwa Lee Heeyoung Kim Jeong Young Park 《Advanced functional materials》2020,30(11)
Precise control of the topology of metal nanocrystals and appropriate modulation of the metal–semiconductor heterostructure is an important way to understand the relationship between structure and material properties for plasmon‐induced solar‐to‐chemical energy conversion. Here, a bottom‐up wet chemical approach to synthesize Au/Ni2P heterostructures via Pt‐catalyzed quasi‐epitaxial overgrowth of Ni on Au nanorods (NR) is presented. The structural motif of the Ni2P is controlled using the aspect ratio of the Au NR and the effective micelle concentration of the C16TAB capping agent. Highly ordered Au/Pt/Ni2P nanostructures are employed as the photoelectrocatalytic anode system for water splitting. Electrochemical and ultrafast absorption spectroscopy characterization indicates that the structural motif of the Ni2P (controlled by the outer‐shell deposition of Ni) helps to manipulate hot electron transfer during surface plasmon decay. With optimized Ni2P thickness, Pt‐tipped Au NR with an aspect ratio of 5.2 exhibits a geometric current density of 10 mA cm?2 with an overpotential of 140 mV. The photoanode displays unprecedented long‐term stability with continuous chronoamperometric performance of 50 h at an input potential of 1.5 V with over 30 days. This work provides definitive guidance for designing plasmonic–catalytic nanomaterials for enhanced solar‐to‐chemical energy conversion. 相似文献
962.
Pingli Qin Tong Wu Zhengchun Wang Lan Xiao Liang Ma Feihong Ye Lun Xiong Xiangbai Chen Haixia Li Xueli Yu Guojia Fang 《Advanced functional materials》2020,30(12)
The plasmonic characteristic of core–shell nanomaterials can effectively improve exciton‐generation/dissociation and carrier‐transfer/collection. In this work, a new strategy based on core–shell Au@CdS nanospheres is introduced to passivate perovskite grain boundaries (GBs) and the perovskite/hole transport layer interface via an antisolvent process. These core–shell Au@CdS nanoparticles can trigger heterogeneous nucleation of the perovskite precursor for high‐quality perovskite films through the formation of the intermediate Au@CdS–PbI2 adduct, which can lower the valence band maximum of the 2,2,7,7‐tetrakis(N,N‐di‐p‐methoxyphenyl‐amine)9,9‐spirobifluorene (Spiro‐OMeTAD) for a more favorable energy alignment with the perovskite material. With the help of the localized surface plasmon resonance effect of Au@CdS, holes can easily overcome the barrier at the perovskite/Spiro‐OMeTAD interface (or GBs) through the bridge of the intermediate Au@CdS–PbI2, avoiding the carrier accumulation, and suppress the carrier trap recombination at the Spiro‐OMeTAD/perovskite interface. Consequently, the Au@CdS‐based perovskite solar cell device achieves a high efficiency of over 21%, with excellent stability of ≈90% retention of initial power conversion efficiencies after 45 days storage in dry air. 相似文献
963.
Daniel Sando Mengjiao Han Vivasha Govinden Oliver Paull Florian Appert Ccile Carrtro Johanna Fischer Agns Barthlmy Manuel Bibes Vincent Garcia Stphane Fusil Brahim Dkhil Jean Juraszek Yinlian Zhu Xiuliang Ma Valanoor Nagarajan 《Advanced functional materials》2020,30(22)
Domain switching pathways fundamentally control performance in ferroelectric thin film devices. In epitaxial bismuth ferrite (BiFeO3) films, the domain morphology is known to influence the multiferroic orders. While both striped and mosaic domains have been observed, the origins of the latter have remained unclear. Here, it is shown that domain morphology is defined by the strain profile across the film–substrate interface. In samples with mosaic domains, X‐ray diffraction analysis reveals strong strain gradients, while geometric phase analysis using scanning transmission electron microscopy finds that within 5 nm of the film–substrate interface, the out‐of‐plane strain shows an anomalous dip while the in‐plane strain is constant. Conversely, if uniform strain is maintained across the interface with zero strain gradient, striped domains are formed. Critically, an ex situ thermal treatment, which eliminates the interfacial strain gradient, converts the domains from mosaic to striped. The antiferromagnetic state of the BiFeO3 is also influenced by the domain structure, whereby the mosaic domains disrupt the long‐range spin cycloid. This work demonstrates that atomic scale tuning of interfacial strain gradients is a powerful route to manipulate the global multiferroic orders in epitaxial films. 相似文献
964.
Jiaoyi Ning Yanan Zhu Zhao Hu Yuhao Shi Muhammad Umair Ali Junpeng He Yaowu He Feng Yan Shihe Yang Jingsheng Miao Hong Meng 《Advanced functional materials》2020,30(35)
Ion migration induced interfacial degradation is a detrimental factor for the stability of perovskite solar cells (PSCs) and hence requires special attention to address this issue for the development of efficient PSCs with improved stability. Here, an “S‐shaped, hook‐like” organic small molecule, naphthalene diimide derivative (NDI‐BN), is employed as a cathode interface layer (CIL) to tailor the [6,6]‐phenylC61‐butyric acid methylester (PCBM)/Ag interface in inverted PSCs. By realizing enhanced electron extraction capability via the incorporation of NDI‐BN, a peak power conversion efficiency of 21.32% is achieved. Capacitance–voltage measurements and X‐ray photoelectron spectroscopy analysis confirmed an obvious role of this new organic CIL in successfully blocking ionic diffusion pathways toward the Ag cathode, thereby preventing interfacial degradation and improving device stability. The molecular packing motif of NDI‐BN further unveils its densely packed structure with π–π stacking force which has the ability to effectually hinder ion migration. Furthermore, theoretical calculations reveal that intercalation of decomposed perovskite species into the NDI clusters is considerably more difficult compared with the PCBM counterparts. This substantial contrast between NDI‐BN and PCBM molecules in terms of their structures and packing fashion determines the different tendencies of ion migration and unveils the superior potential of NDI‐BN in curtailing interfacial degradation. 相似文献
965.
Attila Kormnyos Egon Kecsenovity Alireza Honarfar Tnu Pullerits Csaba Janky 《Advanced functional materials》2020,30(31)
In this study, the photoelectrochemical behavior of electrodeposited FeNiOOH/Fe2O3/graphene nanohybrid electrodes is investigated, which has precisely controlled structure and composition. The photoelectrode assembly is designed in a bioinspired manner where each component has its own function: Fe2O3 is responsible for the absorption of light, the graphene framework for proper charge carrier transport, while the FeNiOOH overlayer for facile water oxidation. The effect of each component on the photoelectrochemical behavior is studied by linear sweep photovoltammetry, incident photon‐to‐charge carrier conversion efficiency measurements, and long‐term photoelectrolysis. 2.6 times higher photocurrents are obtained for the best‐performing FeNiOOH/Fe2O3/graphene system compared to its pristine Fe2O3 counterpart. Transient absorption spectroscopy measurements reveal an increased hole‐lifetime in the case of the Fe2O3/graphene samples. Long‐term photoelectrolysis measurements in combination with Raman spectroscopy, however, prove that the underlying nanocarbon framework is corroded by the photogenerated holes. This issue is tackled by the electrodeposition of a thin FeNiOOH overlayer, which rapidly accepts the photogenerated holes from Fe2O3, thus eliminating the pathway leading to the corrosion of graphene. 相似文献
966.
制备了Al/Al_2O_3/InP金属氧化物半导体(MOS)电容,分别采用氮等离子体钝化工艺和硫钝化工艺处理InP表面。研究了在150、200和300 K温度下样品的界面特性和漏电特性。实验结果表明,硫钝化工艺能够有效地降低快界面态,在150 K下测试得到最小界面态密度为1.6×1010 cm-2·eV-1。与硫钝化工艺对比,随测试温度升高,氮等离子体钝化工艺可以有效减少边界陷阱,边界陷阱密度从1.1×1012 cm-2·V-1降低至5.9×1011 cm-2·V-1,同时减少了陷阱辅助隧穿电流。氮等离子体钝化工艺和硫钝化工艺分别在降低边界陷阱和快界面态方面有一定优势,为改善器件界面的可靠性提供了依据。 相似文献
967.
Haorui Shen Fulai Qi Hucheng Li Pei Tang Xuning Gao Shan Yang Zichen Hu Zhuangnan Li Jun Tan Shuo Bai Feng Li 《Advanced functional materials》2021,31(48):2103309
Lithium dendrites caused by nonuniform Li+ flux leads to the capacity fade and short-circuit hazard of lithium metal batteries. The solid electrolyte interface (SEI) is critical to the uniformity of Li+ flux. Here, an ultrafast preparation of uniform and vertical Cu7S4 nano-flake arrays (Cu7S4 NFAs) on the Cu substrate is reported. These arrays can largely improve the lithiophilicity of the anode and form Li2S-enriched SEI due to the electrochemical reduction of Cu7S4 NFAs with lithium. A further statistical analysis suggests that the SEI, with a higher content of Li2S, is more effective to inhibit the formation of lithium dendrites and yields less dead lithium. A quite stable coulombic efficiency of 98.6% can be maintained for 400 cycles at 1 mA cm–2. Furthermore, at negative to positive electrode capacity ratio of 1.5 (N/P = 1.5), the full battery of Li@Cu7S4 NFAs||S shows 83% capacity retention after 100 cycles at 1 C, much higher than that of Li@Cu||S (33%). The findings demonstrate that high Li2S content in the SEI is crucial for the dendrite inhibition to achieve better electrochemical performance. 相似文献
968.
Dmitry V. Averyanov Ivan S. Sokolov Igor A. Karateev Alexander N. Taldenkov Oleg A. Kondratev Oleg E. Parfenov Andrey M. Tokmachev Vyacheslav G. Storchak 《Advanced functional materials》2021,31(36):2104925
Integration of oxides with silicon fuses advanced functional properties with a mature technological platform. In particular, direct EuO/Si contact holds high promise for spintronics but requires single-crystalline epitaxial films with atomically sharp interfaces. The standard approach employing regular 2D superstructures of metal atoms on the Si surface fails to meet the challenge. Here, an alternative route is designed and shown to solve the problem. This route avoids regular templates; the chaotic 2D distribution of metal atoms on the Si surface prevents stabilization of unwanted crystal orientations. Thus, the disordered submonolayer phase at the interface promotes order in oxide/Si coupling, as witnessed by a combination of diffraction techniques and high-resolution electron microscopy. The results not only mark tangible progress in manufacturing EuO/Si contacts but also provide a general framework for monolithic integration of functional oxides with semiconductor substrates. 相似文献
969.
Xiao Liu Tianhao Wu Caiyi Zhang Yiqiang Zhang Hiroshi Segawa Liyuan Han 《Advanced functional materials》2021,31(50):2106560
Lead-free tin perovskite solar cells (PSCs) have emerged as a promising candidate toward high-performance and eco-friendly photovoltaic technology with great potential for future application. However, tin PSCs with over 10% efficiency usually feature an organic hole transport layer (HTL) at the illumination side that may induce device degradation during long-term operation. Removing the unstable organic HTL is an important way to solve these stability issues, but the efficiency of HTL-free tin PSCs is still much lower than that of the completed cells. Herein, it is demonstrated that formamidinium tin iodide doped with heterogeneous ammonium salts can form an upward band-bending structure to selectively extract the hole in the HTL-free devices. By using this band-bending structure, a promising efficiency of over 10% is first achieved for the lead-free PSCs with a HTL-free structure. More importantly, the optimized cell is highly stable, keeping 95% and 90% of the initial efficiency after continuous light soaking for 40 days and 80 °C annealing for 300 h, respectively. This work paves a route toward the development of efficient, eco-friendly, and highly stable perovskite photovoltaics. 相似文献
970.
Teng Fei Shenqiang Zhai Jinchuan Zhang Ning Zhuo Junqi Liu Lijun Wang Shuman Liu Zhiwei Jia Kun Li Yongqiang Sun Kai Guo Fengqi Liu Zhanguo Wang 《半导体学报》2021,42(11):57-62
Robust quantum cascade laser(QCL)enduring high temperature continuous-wave(CW)operation is of critical import-ance for some applications.We report on the realization of lattice-matched InGaAs/lnAIAs/InP QCL materials grown by metal-organic chemical vapor deposition(MOCVD).High interface quality structures designed for light emission at 8.5μmare achieved by optimizing and precise controlling of growth conditions.A CW output power of 1.04 W at 288 K was obtained from a 4 mm-long and 10 μm-wide coated laser.Corresponding maximum wall-plug efficiency and threshold current density were 7.1%and 1.18 kA/cm2,respectively.The device can operate in CW mode up to 408 K with an output power of 160 mW. 相似文献