Two-dimensional (2D) transition-metal dichalcogenides (TMDCs) have gained considerable attention as an emerging semiconductor due to their promising atomically thin film characteristics with good field-effect mobility and a tunable band gap energy. However, their electronic applications have been generally realized with conventional inorganic electrodes and dielectrics implemented using conventional photolithography or transferring processes that are not compatible with large-area and flexible device applications. To facilitate the advantages of 2D TMDCs in practical applications, strategies for realizing flexible and transparent 2D electronics using low-temperature, large-area, and low-cost processes should be developed. Motivated by this challenge, we report fully printed transparent chemical vapor deposition (CVD)-synthesized monolayer molybdenum disulfide (MoS) phototransistor arrays on flexible polymer substrates. All the electronic components, including dielectric and electrodes, were directly deposited with mechanically tolerable organic materials by inkjet-printing technology onto transferred monolayer MoS, and their annealing temperature of <180 °C allows the direct fabrication on commercial flexible substrates without additional assisted-structures. By integrating the soft organic components with ultrathin MoS, the fully printed MoS phototransistors exhibit excellent transparency and mechanically stable operation.

By the combination of the inkjet printing of PEDOT:PSS transfer template and selective transfer of silver nanowires (AgNW), AgNWs of customizable transparency can be patterned with high degree of freedom, without need of high equipment cost and complicated process. The AgNW‐transferred PEDOT:PSS transparent electrodes exhibit both great figure of merit and easily tunable optoelectronic properties. With maintaining the advantages and overcoming the issues of the AgNWs, the method developed by Yongtaek Hong and co‐workers in article number 2000042 can be applied to various flexible electronics.

Inkjet and transfer printing processes are combined to easily form patterned poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films as top anodes of all solution-processed inverted polymer light emitting diodes (PLEDs) on rigid glass and flexible plastic substrates. An adhesive PEDOT:PSS ink is formulated and fully customizable patterns are obtained using the inkjet printing process. In order to transfer the patterned PEDOT:PSS films, adhesion properties at interfaces during multistep transfer printing processes are carefully adjusted. The transferred PEDOT:PSS film on the plastic substrates shows not only a sheet resistance of 260.6 Ω/□ and a transmittance of 92.1% at 550 nm wavelength but also excellent mechanical flexibility. The PLEDs with spin-coated functional layers sandwiched between the transferred PEDOT:PSS top anodes and inkjet-printed Ag bottom cathodes are fabricated. The fabricated PLEDs on the plastic substrates show a high current efficiency of 10.4 cd A −1 and high mechanical stability. It is noted that because both Ag and PEDOT:PSS electrodes can be patterned with a high degree of freedom via the inkjet printing process, highly customizable PLEDs with various pattern sizes and shapes are demonstrated on the glass and plastic substrates. Finally, with all solution process, a 5 × 7 passive matrix PLED array is demonstrated.

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Seamless tiling of displays is one of the key enabling technologies for the next-generation large-area electronics applications. In this paper, we propose a facile method to demonstrate a seamless display using cylindrical lens pair (CLP) fabricated by dispenser printing method. Optical properties of the printed CLP and corresponding capability of concealing seam in the display are analyzed by a set of luminance simulation and measurement in terms of geometric parameters of the lens. The seamless display with an optimized CLP features a viewing angle of the seam concealment of 40°.

Conductive thin films are typically subject to crack formation and propagation under tensile strain, turning into insulating films due to complete breakage at large strain. However, if such crack propagation can be intentionally designed, repetitive resistance change can be obtained and used for implementation of high-performance strain sensors that are suitable for biocompatible and stretchable electronic applications. In this work, therefore, we introduce a fiber-reinforced region, which is formed by additionally inkjet-printing a single-walled carbon nanotube thin film, in a poly(3, 4-ethylenedioxythophene) doped with poly(styrenesulfonic acid) (PEDOT: PSS) thin film. The fiber-reinforced region well suppresses the crack propagation in the film under the tensile strain. The engineered PEDOT:PSS films are used to fabricate a strain sensor with a high gauge factor of ∼9 (at 50% strain) and an excellent working range of 70% even after 1000 cycle test at 50% tensile strain. Such a high-performance is explained via different fracture mechanisms between the fracture-designed and the fiber-reinforced regions in the PEDOT:PSS films. Our strategy of designing crack propagation using the inkjet-printing process enables not only to fabricate high-performance strain sensors that can detect human motions but also to provide a new insight for highly contuctive, but relatively brittle, materials toward the stretchable electronics applications.

The solution-processed gallium-doped zinc oxide (GZO) layer was used as an anode-flattening photonic-crystal (PC) underlayer to enhance the light outcoupling of polymer light-emitting diodes (PLEDs). A corrugated PC surface was directly coated with GZO, which acted as a planarization layer as well as an anode. The PLEDs with the PC-embedded GZO anode showed higher efficiencies and an effective areal light emission when several PLEDs were formed in an array format. ARTICLE HISTORY