Inkjet Printing of Perovskite Nanosheets for Microcapacitors

Abstract

Dielectric capacitors are an essential passive component widely used in integrated circuits. Recently, inkjet printing of 2D nanosheets into highly insulating layers has been developed for capacitor applications. However, the relatively low dielectric constant inherently associated with 2D nanosheets will hinder the rational design of high‐performance capacitor devices. In this work, the inks of high‐k Ca2NaNb4O13 perovskite nanosheets are formulated, and all‐printed dielectric capacitor consisting of Ca2NaNb4O13 films with commercial Ag electrodes is demonstrated. An average areal capacitance of ≈21 nF cm−2, together with low current density (<10−7 A cm−2) and low dielectric loss (≈2%), is achieved for the dielectric layer with thickness of ≈2 µm. The research shows that high‐k perovskite nanosheets have a great potential for applications in ink‐based additive manufacturing of flexible electronic devices.

Mayer Rod‐Coated Organic Light‐Emitting Devices: Binary Solvent Inks, Film Topography Optimization, and Large‐Area Fabrication

“…When the stainless steel coils are tightly wound onto the Mayer rod surface, the morphology, thickness, and surface roughness of the resulting Mayer rodcoated films are determined by the diameters of stainless steel wire, coating pressures, and coating speeds, as depicted in Figure 2. Various coating conditions with Mayer rods with different coil diameters (4, 12, and 20 μm) at varying coating speeds (5,10,15,20, and 25 m s À1 ) have been investigated for comparison. The optimized coil diameter is 12 μm, and the optimized coating speed is 20 m s À1 .…”

“…[ 7–9 ] Solution‐based deposition methods are proven to be reliable techniques in realizing high‐performance and large‐area mass production of flexible/wearable optoelectronic devices, especially printing techniques. [ 10–14 ] A variety of printing methods have been developed, such as inkjet printing, [ 15–18 ] spraying, [ 19,20 ] gravure printing, [ 21–23 ] roll to roll, [ 24,25 ] and Mayer rod coating. [ 26–28 ]…”

“…[7][8][9] Solution-based deposition methods are proven to be reliable techniques in realizing high-performance and large-area mass production of flexible/wearable optoelectronic devices, especially printing techniques. [10][11][12][13][14] A variety of printing methods have been developed, such as inkjet printing, [15][16][17][18] spraying, [19,20] gravure printing, [21][22][23] roll to roll, [24,25] and Mayer rod coating. [26][27][28] Nevertheless, these printing techniques suffer from inherent restrictions, for example, a specific viscosity or surface tension window, which is required for printing functional inks to construct highperformance printed electronics.…”

“…[29,30] In this context, appropriate functional ink formulations for a specific printing method must be developd to form large-area uniform pinhole-free films on the nanoscale. [15,18,23,28] Research on the general principle for printing functional ink formulation is desirable, but it is also rather challenging.…”

Fully 3D‐Printed, Ultrathin Capacitors via Multi‐Material Microsputtering

“…More recently, Fu and colleagues reported inkjet-printed capacitors that require a lower (200 °C) annealing temperature; the dielectric layer was 2 µm thick, made with a novel perovskite ink, while the electrodes had micrometer-scale thickness and were made using a commercially available silver ink. [39] This paper reports the first fully additively manufactured capacitors as a proof-of-concept demonstration of direct-write, ultrathin-film electronic components made via low-temperature, atmospheric pressure, multi-material microplasma sputtering. Ultrathin metal and dielectric films are deposited at room temperature and pressure conditions on a substrate using a novel, continuously fed, dual target microsputtering printhead.…”