Zijie Xu

Ultraflexible, stretchable and fast-switching electrochromic devices with enhanced cycling stability

Ultraflexible electronics have received extensive attention due to their favorable properties, such as superior mechanical robustness, light weight and good compatibility with large-area roll-to-roll fabrication. Here we present a flexible sandwiched tungsten trioxide/silver nanotrough network/poly(3,4-ethylenedioxythiophene)–poly(styrene sulfonate) multi-layer transparent conducting electrode with prominent conductivity (sheet resistance as low as 1.08 Ω sq−1) and transparency (85%). In particular, the flexible transparent electrode exhibits excellent mechanical robustness upon bending and stretching. This hybrid electrode can be further adhered tightly to a layer of WO3 to form an electrochromic device, which simultaneously displays a rapid switching time (0.75 s/1.82 s for bleaching/coloring) and high cyclic performance (86% retention of the initial optical contrast after cycling for 30 000 s). In addition, our electrode can also be fabricated on various flexible substrates, such as polyethylene cling wrap, polydimethylsiloxane and Ecoflex, with sustained electrochromic properties after bending, twisting, stretching and even strong kneading. Our work provides new opportunities for the next generation of flexible and wearable electronics applied on various flexible substrates.

Data analysis between controllable variables and the performance of CuS crackle based electrode

In this article, we provide the data analysis between controllable variables and the performance of CuS crackle based electrode, there are four important factors which could influence the formation of cracks, the colloid concentration, drying temperature, colloid dosage and ambient humidity. We carried out and summed nineteen controlled data experiments below and other variates which could affect the performance were discussed in this article.

Metal-based semiconductor nanomaterials for thin-film solar cells

Abstract Searching for “green,” renewable, and sustainable energy resources is one of the most urgent challenges our civilization faces, particularly as it relates to the threat of energy crises and environmental pollution. As one of the most promising renewable energy resources for the future, solar cells have received extensive attention. The metal-based semiconductor layer plays a critical role in the functioning of most thin-film solar cells, acting as a mesoporous layer for active adsorption of materials, as a charge transport medium layer for electron transport, and as an interfacial layer to reduce charge recombinations. Therefore, in this chapter, we present an overview of the latest developments in several commonly used metal-based semiconductor nanomaterials, mainly TiO 2 , ZnO, SnO 2 , Al 2 O 3 , and Nb 2 O 5 in different solar cells, such as dye-sensitized solar cells (DSSCs), quantum-dot sensitized solar cells (QDSCs), perovskite solar cells (PSCs), and organic solar cells (OSCs). Two groups of metal-based semiconductor layers are categorized according to their unique features: (i) semiconductor nanomaterials as interfacial materials for solar cells and (ii) semiconductor nanomaterials as mesoporous layers for solar cells. We focus on the fabrication techniques utilized for the synthesis of efficient nanostructured semiconducting electrodes, the application of these nanostructured semiconducting materials in solar cells and their impact on the output of the devices, and the role of different interfacial layers used in improving the output of the device. Finally, we present a brief summary as well as some perspectives on the current challenges and opportunities in order to help researchers better understand this emerging area of research.

Controllable and large-scale fabrication of flexible ITO-free electrochromic devices by crackle pattern technology

Electrochromic devices (ECDs) presenting reversible color variation are considered as the most promising alternative to traditional smart windows. However, the fabrication of large-scale ECDs with high flexibility and stability is still challenging. In this work, we present a crackle pattern technology for controllable and large-scale fabrication of rectangular Ag network films for indium tin oxide-free (ITO-free) flexible ECDs. This rectangular Ag film exhibits superior mechanical robustness and controllable optoelectronic performance (2.0 Ω sq−1 at 91% transmittance). In the application of WO3 based ECD, the rectangular film presents an ultrafast switching time (0.25/0.18 s for bleaching/coloring) and is thus applicable in flexible displays. Moreover, this device demonstrates a large optical modulation of 76% at 630 nm and sustains 78.9% of its initial modulation even after 20 000 cycles, which is close to the commercial standard for rigid ECDs. The obtained rectangular Ag films are successfully assembled into a flexible all-solid-state ECD (21 × 13 cm2), which can be utilized in smart windows, glasses and other fields that require bending or cutting.