Submicron copper inks can be sintered at a low temperature of 140 °C by the in situ generation of fresh copper nuclei.

A simple sol−gel solution route for the synthesis of α-phase molybdenum trioxide (α-MoO 3 ) nanorods is investigated in terms of growth mechanism with controlling the citric acid decomposition rate. The singlephase and single-crystal nanorod arrays of MoO 3 grown in random directions from a silica glass substrate had mean diameters and lengths of 10 and 500 nm, respectively, as determined through chemical analysis. The citric acid plays a critical role for the nanorods growth process from investigating the relative molar ratio of molybdate and citric acid in the precursor. Moreover, the dissociation timing of the citric acid, which was controlled by the other two synthesis parameters, i.e., sintering time and solvents, also greatly influences growth and phase transition of the MoO 3 nanorods, which was analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The synthesis parameters were optimized to design the length and density of the nanorod arrays. The longest nanorods can be obtained up to 600 nm using a dimethylacetamide solvent, a molar ratio of Mo:citric acid = 0.5:1.5, and sintering at 673 K for 15 min in an ambient atmosphere. Findings of the present study describe that the factors of the nanorods' growth and phase changing are deeply correlated with disassemble steps of the Mo metal−citric acid complex in the sol−gel precursor solution, which may contribute to applying the material development in several electronic devices using MoO 3 nanostructures.

In this study, an ultra‐thin MoO3 layer synthesized by a solution‐based technique is introduced as a promising interfacial layer to improve the performance of kesterite Cu2ZnSnSe4 (CZTSe) solar cell. Solar cells with 10 nm of MoO3 between Mo rear contact and CZTSe had larger minority carrier life time and open‐circuit voltage compared to the reference solar cells. Temperature dependent current density–voltage measurement indicated that the activation energy (EA) of the main recombination is higher (∼ 837 meV) in solar cells with MoO3 layer, as compared to conventional solar cells where EA ∼ 770 meV, indicating reduced interface recombination. A best efficiency of 7.1% was achieved for a SLG/Mo/MoO3/CZTSe/CdS/TCO solar cell compared to the reference solar cell SLG/Mo/CZTSe/CdS/TCO for which 5.9% efficiency was achieved.

attention from researchers because of their advantages of sensitivity, rapid response, and inexpensive production. [9,10] Recently, considerable effort has been devoted to developing much simpler routes to control the shape and grain size of SMO to achieve a higher surface-to-area ratio and unique surface chemistry behavior to improve sensing performance. [11][12][13] Among the metal oxides, molybdenum trioxide (MoO 3 ) is one of the most desirable for use in gas sensors because of its indirect wide band gap of 3.5 eV. [14][15][16][17] MoO 3 -based gas analyzing devices show excellent gas sensing properties for several kinds of gas species [18][19][20][21][22][23][24] because of their special quantum size effect, surface effect, high reactivity, and the polyvalency of molybdate. In particular, MoO 3 nanostructures, such as MoO 3 nanobelts, flower-like microstructured MoO 3 , and net-like MoO 3 porous architectures synthesized by the hydrothermal route, exhibit appealing sensing properties for VOC vapors. [25][26][27] The gas sensing properties of MoO 3 thin film fabricated by radiofrequency (RF) sputtering have also been investigated. [28] These reports showed the nanostructures possessed typical sensing performance for VOC vapors; however, these nanostructures need to be processed with two or more steps, which is time consuming. For instance, these nanostructures need to be transferred or arranged on a ceramic substrate and then annealed to obtain substantial growth/adhesion on the substrate. To increase the VOC gas sensing performance of nanostructures, they needed to be loaded with noble metal particles (e.g., Au, Nanorod arrays gas sensors are attracting much scientific and engineering interest because of their excellent sensing performance arising from their unique nanostructures. In this work, large-scale random 3D networks of ultrafine single-crystal α-MoO 3 nanorod arrays are applied as gas sensors. The arrays are spontaneously grown by a simple single-step solution route. A prompt response and obvious discrimination of ethanol, methanol, isopropanol, and acetone vapors at 573 K are investigated via the modulation of the resistance of the gas sensors. The sensitivity, response time, and recovery time of the sensors strongly depend on the specific morphologies of the nanorod arrays, such as length, number, and coverage of nanorods in the 3D network. A reaction mechanism in which the 3D-network nanorod arrays adsorb and react with the target molecules more readily than the seed layer is proposed to explain the different response and recovery times of the sensors. These random 3D-network nanorod arrays with functionally tunable morphology are promising for universal application as gas sensors for detecting various vapors, and provide valuable insights for the production of fast, largescale, low-cost, and simple synthesis of sensing devices.

Single‐ and multi‐layer transparent conductive oxide (TCO) thin films exhibiting high performance, good packing density and low surface/interface roughness are deposited on silica glass substrates by the sol–gel method. The crystal and microstructural properties of the TCO thin films are evaluated as an alternate to films prepared by ultra‐high vacuum deposition. Tin‐doped indium oxide (ITO) thin films produced using a two‐step drying process showed low surface roughness because of dense packing structure not only horizontal but also vertical directions. As a result, electrical conductivity, carrier concentration, carrier mobility, and optical transmittance of 2.3 × 103 S/cm, 8 × 1020 cm−3, 18 cm2/Vs, and over 98% at 500 nm, respectively, were achieved. A multilayer ZnO/ITO stacked structure was also fabricated using the sol–gel process. Our findings suggest that solution‐based methods show promise as an alternative to existing ultra‐high vacuum methods to fabricate TCO thin films.

Simple solution process were developed to fabricate efficient MoOx based HTLs for organic solar cells.

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3D‐network of ultra‐fine single‐crystal α‐MoO3 nanorod array based gas sensors show a prompt response and discrimination to volatile organic compounds (VOCs). S. Cong, T. Sugahara, and co‐workers illustrate that performance of the sensors strongly depends on the specific morphologies of the nanorod arrays, such as length, number and coverage of nanorods in the 3D network in the article 1600252. The nanorod arrays are spontaneously grown with functionally tunable morphology by a simple single‐step solution route. The conductance modulation of the nanorod arrays is attributed to hydrogen ions decomposed from VOCs intercalated into the van de Waals's gaps of layered α‐MoO3 and the subsequent reduction of cornered oxygen to H2O.