stability when compared to their counterparts. [4] Currently existing technologies for commercial applications of TFTs use vacuum-based deposition methods and photolithographic patterning of the layers to ensure a high manufacturing yield.Due to the availability of inexpensive precursors, ease of fabrication, and applicability for large-area processing, solutionprocessed methods may offer low-cost routes for the manufacturing of oxidebased TFTs. [5] Specifically, printing offers an advantage by eliminating the necessity of photolithographic patterning of the deposited layers. However, there are still several challenges before the realization of flexible electronics based on printed oxides, and one of them is the requirement of a hightemperature post deposition annealing (PDA) of the printed layers. [6] To reduce the PDA temperature of the solution-processed layers, several methods such as deep ultraviolet (DUV) annealing, [7][8][9] flash lamp annealing, [10,11] microwave annealing, [12] and solution combustion synthesis [13][14][15][16] have been proposed for semiconductor, conductor, and dielectric layers. DUV annealing (annealing method in this study) is based on the absorption of the deep UV light (λ < 260 nm) by the precursors used in the solution-processed deposition resulting in their decomposition into active oxide layers. DUV has been demonstrated to be applicable not only to oxide dielectrics but also to the semiconductors such as indium oxide, IGZO, and indium zinc oxide. [8] As a major component of the TFT, the dielectric layer is crucial for achieving high-performance devices. The effective polarization of charges in the dielectric under the applied gate bias directly affects the amount of charges accumulated/ depleted in the channel material, which in turn indicates the switching performance of the transistor. Up to now, the majority of low-temperature solution-processed dielectric layers have been reported using spin coating methods, aiming at uniform and pinhole-free layers. [17] Several binary oxide dielectrics with high dielectric constants (high-κ) such as AlO x , YO x , HfO x , and ZrO x have been investigated for their use in oxide TFTs, and the devices with higher mobilities and lower threshold voltages rather than the devices employing SiO 2 insulators Recent developments in inkjet printing have proven it a viable method for low-cost and large-area coating of oxide materials. The main drawback of this method is the common requirement of a post-deposition annealing (PDA) of the printed layers at relatively high temperatures (T > 200 °C). This sets a requirement for the substrate to have high glass transition temperature (T g ). Toreduce the PDA temperature, deep-ultraviolet (DUV) annealing is proposed as an effective method. In this study, yttrium aluminum oxide (YAlO x ) dielectrics are realized for application in flexible electronic devices via inkjet printing and DUV annealing at a temperature of 150 °C. The effect of the Y concentration on the electrical properties of the dielectrics is i...

The aim of this work was to investigate the influence of morphology on its electrochemical properties by comparing ZnO nanostructures in the forms of tetrapods of different sizes, nanorods, and nanoparticles. ZnO tetrapods were prepared by the combustion method and separated into two fractions by size, ruling out the influence of synthesis conditions. Structural and morphological properties of different ZnO nanostructure morphologies were identified by using various characterization techniques: scanning and transmission electron microscopies (SEM and TEM), X-ray powder diffraction (XRD), nitrogen adsorption/desorption measurements at 77 K, and UV–vis spectroscopy (UV–vis). Analysis of electrochemical properties showed the highest active surface area of 0.095 cm2 and the lowest peak separation value of 61.7 mV for large ZnO tetrapods, which are close to the theoretical values. The correlation between the pore size in different ZnO nanostructures because of packing and their electrochemical properties is established. We expect that the detailed analysis of ZnO nanostructures conducted in this study will be advantageous for future electrochemical and biosensing applications of these materials.

High control chemical vapour deposition of (Cs,FA)PbI3 perovskite provides insights into CVD kinetics and perovskite phase evolution.

Indium tin oxide (ITO) is a transparent conducting material that is widely used in devices where high transparency of the electrodes is required, such as flat panel and liquid crystal displays, touch panels, smart windows, and many others. ITO layers are deposited on a large scale by magnetron sputtering and then structured by lithography to define desired patterns of transparent electrodes. Here, a method for direct printing of transparent conductive patterns from ITO nanoparticle ink is communicated. The method combines inkjet printing with fast flash lamp annealing whereby the main novelty is to use an additional layer of a colored organic dye onto printed ITO to increase light absorption. The dye coating is instantly heated together with the underlying ITO layer by a light pulse, leading to an instant rise of the surface temperature, which is translated into improved optoelectronic properties of the ITO layers. Inkjet‐printed ITO patterns processed with the dye‐assisted flash lamp annealing exhibit a transmittance of up to 88% at 550 nm and resistivity of 3.1 × 10−3 Ω cm. Transparent touch‐sensing trackpad and capacitive touch sensors are demonstrated based on the printed ITO patterns, which can be utilized in transparent security systems and other transparent Internet‐of‐Things devices.

Among various types of perovskite‐based tandem solar cells (TSCs), all‐perovskite TSCs are of particular attractiveness for building‐ and vehicle‐integrated photovoltaics, or space energy areas as they can be fabricated on flexible and lightweight substrates with a very high power‐to‐weight ratio. However, the efficiency of flexible all‐perovskite tandems is lagging far behind their rigid counterparts primarily due to the challenges in developing efficient wide‐bandgap (WBG) perovskite solar cells on the flexible substrates as well as their low open‐circuit voltage (VOC). Here, it is reported that the use of self‐assembled monolayers as hole‐selective contact effectively suppresses the interfacial recombination and allows the subsequent uniform growth of a 1.77 eV WBG perovskite with superior optoelectronic quality. In addition, a postdeposition treatment with 2‐thiopheneethylammonium chloride is employed to further suppress the bulk and interfacial recombination, boosting the VOC of the WBG top cell to 1.29 V. Based on this, the first proof‐of‐concept four‐terminal all‐perovskite flexible TSC with a power conversion efficiency of 22.6% is presented. When integrating into two‐terminal flexible tandems, 23.8% flexible all‐perovskite TSCs with a superior VOC of 2.1 V is achieved, which is on par with the VOC reported on the 28% all‐perovskite tandems grown on the rigid substrate.

Electrically conductive thin-film materials possessing high transparency are essential components for many optoelectronic devices. The advancement in the transparent conductor applications requires a replacement of indium tin oxide (ITO), one of the key materials in electronics. ITO and other transparent conductive metal oxides have several drawbacks, including poor flexibility, high refractive index and haze, limited chemical stability, and depleted raw material supply. Single-walled carbon nanotubes (SWCNTs) are a promising alternative for transparent conducting films (TCFs) because of their unique and excellent chemical and physical properties. Here, the latest achievements in the optoelectronic performance of TCFs based on SWCNTs are analyzed.Various approaches to evaluate the performance of transparent electrodes are briefly reviewed. A roadmap for further research and development of the transparent conductors using "rational design," which breaks the deadlock for obtaining the TCFs with a performance close to the theoretical limit, is also described.

The scalability of highly efficient organic-inorganic perovskite solar cells (PSCs) is one of the remaining challenges of solar module manufacturing. Various scalable methods have been explored to strive for uniform...

The rapid evolution of the neuromorphic computing stimulates the search for novel brain-inspired electronic devices. Synaptic transistors are three-terminal devices that can mimic the chemical synapses while consuming low power, whereby an insulating dielectric layer physically separates output and input signals from each other. Appropriate choice of the dielectric is crucial in achieving a wide range of operation frequencies in these devices. Here we report synaptic transistors with printed aluminum oxide dielectrics, improving the operation frequency of solution-processed synaptic transistors by almost two orders of magnitude to 50 kHz. Fabricated devices, yielding synaptic response for all audio frequencies (20 Hz to 20 kHz), are employed in an acoustic response system to show the potential for future research in neuro-acoustic signal processing with printed oxide electronics.