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ABX3-type organic-inorganic hybrid halide perovskite materials have been recognized as promising candidates for optoelectronic applications. However, poor stability of organic-inorganic hybrid perovskite hinders their forward long-term utilization and hence an effective strategy is needed to replace the organic part with an inorganic cation. Herein, all inorganic CsPbI3nanowires with a diameter of 50–100 nm are synthesized on fluorine-doped tin oxide glass via a simple solution-dipping process, which are further transformed into CsPbBr3nanowires through a solution-phase halide exchange method. A phase change from non-perovskite to perovskite structure is observed during the ion substitution process of I−by Br−, which is elaborated by X-ray diffraction, absorption and photoluminescence spectra. We for the first time apply the as-formed CsPbI3and CsPbBr3nanowires into perovskite solar cells, yielding power conversion efficiency of 0.11% and 1.21%, respectively. The inorganic CsPbBr3nanowire solar cell shows impressive stability which still remains 99% of the initial power conversion efficiency even after 5500 h aging. 有机无机杂化钙钛矿因其优异的光电性能受到广泛关注, 但是其对湿度、热的不稳定性会限制钙钛矿电池的进一步发展. 本文通过简单的溶液浸泡法在导电基底上制备了尺寸为50–100 nm的全无机碘化铅铯纳米线, 并通过离子交换法将碘化铅铯置换成溴化铅铯纳米线. 文章通过X射线衍射谱、紫外可见吸收光谱、荧光发光光谱对I离子交换成Br离子过程进行了研究. 结果发现I-Br离子交换过程中伴随着晶体结构的变化, 起初的碘化铅铯为非钙钛矿结构, 离子交换后制备的溴化铅铯为钙钛矿结构. 本文将全无机卤化铅铯纳米线应用在钙钛矿电池器件中, 器件显示出优越的稳定性, 放置5500小时效率几乎未衰减.

Organometal trihalide perovskite solar cells (PSCs) based on multiple-site alloyed perovskite currently attract a surge of research interests owing to their extreme high solar-to-electric power conversion efficiency (PCE). Additionally, perovskite single crystals, proven to possess lower defect density, are highly anticipated to realize the full potential of perovskite materials. Herein, we for the first time proposes a facile and operable cooling-induced crystallization method to fabricate dual-site alloyed FAxMA1−xPb(IxBr1−x)3single microcrystals with tunable bandgaps, which will later be employed as encouraging precursors to form high quality perovskite films with extended grain sizes and less grain boundaries. The corresponding solar cells showcase advanced charge transport and retarded recombination, leading to satisfying photovoltaic performance and heartening device stability (a champion PCE of 18.3% and a satisfying maintenance of ~83% initial PCE after 2000h aging without encapsulation), indicating a promising protocol of fabricating miscellaneous single microcrystal perovskite precursors for highly efficient PSCs.

Two-dimensional (2D) ZnO nanosheet arrays were prepared via vanadium (V)-doping assisted hydrothermal method, and then the nanosheet was successfully converted to a nanorod-on-nanosheet ZnO hierarchical structure by treating with Na2S solution and subsequent hydrothermal reaction. Hierarchical films with different nanorod growth time (1–8 h) were prepared and their photovoltaic properties were also investigated after electrodeposition of CdSe quantum dots. For the hierarchical nanorod-on-nanosheet ZnO films, increasing the ZnO nanorod growth time can enormously enlarge the length of branched nanorods and light-scattering ability, resulting in better light-harvesting efficiency and higher photo-generated electron concentration, which leads to higher short-circuit current density (Jsc) and open-circuit voltage (Voc). However, further increasing nanorod growth time to 8 h leads to the over-dense coverage of nanorods, which is harmful for light-harvesting efficiency and leads to severe electron recombination, eventually diminishes the power conversion efficiency (PCE). With the optimized nanorod modification and Cu2S counter electrode, the PCE reaches a maximum value of 4.26%, which to the best of our knowledge, is among the highest PCE record for CdSe sensitized solar cells based on ZnO photoanodes.

The development of a novel nanoarray photoanode with a heterostructure on a transparent conducting oxide substrate provides a promising scheme to fabricate efficient energy conversion devices. Herein, we successfully synthesize the vertically aligned hierarchical TiO2nanowire/ZnO nanorod or TiO2nanowire/ZnO nanosheet hybrid arrays, which are proven to be excellent anode candidates for superior light utilization. Consequently, the quantum-dot-sensitized solar cells based on such hybrid arrays exhibit an impressive power conversion efficiency (PCE) under AM 1.5G one sun illumination with improved short-circuit current density (JSC) and fill factor compared to pristine TiO2nanowire arrays. Combined with the chemical-bath-deposited Cu2S counter electrode, the eventual PCE can be further optimized to as high as 4.57% for CdS/CdSe co-sensitized quantum dot solar cells.

The development of an effective anode material with hierarchical multi-dimensional architecture is conducive to further improve the cell performance of photovoltaic devices. Herein we introduce an intriguing three-dimensional (3D) hierarchically branched hollow sphere-nanowire hybrid TiO2photoanode for promising CdS and CdSe quantum dots co-sensitized solar cells application. The demonstrated 3D hierarchically hybrid photoanode owns a considerably high specific surface area while maintaining roomy space and providing ample porosity for efficient electrolyte infiltration. Moreover, the outstanding light scattering ability of such multi-dimensional architecture leads to an enhancement of light utilization efficiency and thus significantly enhanced short-circuit photocurrent. The control over the pore size of TiO2hollow spheres and the optimizations on the newly developed chemical bath deposited (CBD) cuprous sulfide (Cu2S)/FTO counter electrode eventually yields power conversion efficiency as high as 6.01% for CdS/CdSe based quantum dot-sensitized solar cells (QDSSCs).

The high-performance of a well-aligned 1D nanostructured electrode relies largely on a smart and rational modification with other active nanomaterials. Herein, we present a facile solution-based route to fabricate a well-aligned metal oxide-based core–shell hybrid arrays on TCO substrate. Demonstrated samples included nanowire@nanoparticle (TNW@NP) or nanowire@nanosheet (TNW@NS) with a unique porous core/shell nanowire arrays architecture in the absence or presence of DETA during the solvothermal treatment process. The “alcoholysis” and “ripening” growth mechanism is proposed to explain the formation of honeycomb-like nanosheets shell on nanowires core. Based on careful control of experimental condition, a novel double layered TiO2photoanode (DL-TNW@NS-YSHTSs) consisting of 16 μm thick TNW@NS under layer and 6 μm thick yolk–shell hierarchical TiO2microspheres (YSHTSs) top layer can be obtained, exhibiting an impressive PCE over 10% at 100 mW cm–2, which can be attributed to the well-organized photoanode composed of hierarchical core–shell arrays architecture and yolk–shell hollow spheres architecture with synergistic effects of high dye loading and superior light scattering for prominent light harvesting efficiency.

A powerful full solution-based process was demonstrated to synthesize various vertically aligned TiO2wires/rods self-assembled arrays nanostructures on conductive substrates via a simple hydrothermal growth system. Demonstrated samples included a family of high-quality and high-crystallinity anatase nanowire arrays with smooth, hierarchical or hyperbranched architectures, thanks to oriented attachment and crystallization as well as a self-assembly growth mechanism. The proposed hyperbranched arrays, consisting of long TiO2nanowire trunks, short TiO2nanorod branches as well as tiny TiO2nanorod leaves (recall a tree with luxuriant foliage) and thus possessing a microscopic feature size, overcome typical shortages of insufficient dye adsorption for conventional 1D smooth nanowire arrays or prototype hierarchical nanowire arrays when applied to DSSC, which achieved for the first time similar dye uptakes (i.e.90.10nmolcm−2vs88.62nmolcm−2) as nanoparticle counterparts under the same thickness. Dye-sensitized solar cell fabricated with an ~8μm long novel hyperbranched nanowire arrays photoelectrode yields an impressive power conversion efficiency (PCE) of 8.11%, which was much greater than that of anatase TiO2nanoparticle (20nm in diameter) counterpart due to synergistic effects of high dye uptakes and superior broadband light scattering for improved light harvesting as well as fast charge transport for efficient charge collection for the former.

The vertically aligned anatase TiO2nanowire arrays with smooth or branched architectures were grown on TCO substrate directly via a simple surfactant-free hydrothermal route. And they were utilized to fabricate efficient quantum-dot sensitized solar cells (QDSSCs) for the first time. The thickness of CdS and CdSe shell were confirmed by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and energy dispersive X-Ray spectroscopy (EDX). A power conversion efficiency of 4.2% was attained with the hierarchical TiO2nanowires based cell, which is 30% higher than that of smooth nanowires devices due to improved short-circuit current density (JSC) and fill factor (FF). The increased JSCprofits from superior light-scattering ability of branched hierarchical TiO2nanowires for enhanced light-harvesting efficiency and the prominent charge-collection efficiency benefited from additional growth of branches for efficient and effective electron injection.

An engineered and optimized trilayered TiO2photoelectrode on Ti metal substrates with synergistic effects for dye-sensitized solar cells has been developed through the combination of one-dimensional (1D) TiO2nanotubes, three-dimensional (3D) TiO2hierarchical microsized spheres, as well as zero-dimensional (0D) nanoparticles with a large surface area. The advantages of efficient charge-collection, light-harvesting, as well as high dye-loading capability make it possible to achieve unprecedentedly high short-circuit photocurrent density (17.90 mA cm–2) under back-side illumination and thus allow us to obtain a power conversion efficiency as high as 9.10%.

A hierarchical macroporous Zn2SnO4–ZnO nanorod composite film is prepared through a drop-casting process of PS@Zn2SnO4and subsequent hydrothermal growth of ZnO nanorod. CdS/CdSe co-sensitized solar cells based on the macroporous Zn2SnO4–ZnO nanorod composite photoelectrode exhibits an enhancement of 34.4% in power conversion efficiency (1.68%) compared to the pristine macroporous Zn2SnO4photoelectrode (1.25%). Especially worth noting is that the growth of ZnO nanorods contributes greatly to the enlargement of surface area and improvement of light scattering ability of the composite film, which dominates the increase of Jscvalues and eventual power conversion efficiency. QDSSCs based on the optimized 9 μm thick composite photoanode film exhibits a power conversion efficiency of 2.08%, which is the highest value for the reported QDs sensitized solar cells based on the Zn2SnO4photoelectrode.

The aim of this article is to provide a systematic method to perform experimental test and theoretical evaluation on adhesion properties of the Cr/Al interface structure. A specified Cr/Al interface film assembly was deposited on the quartz glass by using RF magnetron sputtering. The elastic modulus and the hardness of the sample are tested by the nanoindentation tester. The test results show that the elastic modulus and the hardness of the sample have a nonlinear characteristic with different depth h of the interface structure. In the meantime, a finite element model is built to simulate the interface characteristics of the sample. The analysis shows that the stress mainly centralizes close to the top of the nanoindentation tester and the maximum stress occurs in the second layer Al film, not the first layer Cr film. The comparison between the test and the simulation shows the validity of the experimental test and the modeling method of each other. It builds a basis for future work such as fabrication of Cr/Al interface structure for micro/nano manufacturing.