Highly Conductive Networks of Silver Nanosheets

Abstract

Although printed networks of semiconducting nanosheets have found success in a range of applications, conductive nanosheet networks are limited by low conductivities (<106 S m−1). Here, dispersions of silver nanosheets (AgNS) that can be printed into highly conductive networks are described. Using a commercial thermal inkjet printer, AgNS patterns with unannealed conductivities of up to (6.0 ± 1.1) × 106 S m−1 are printed. These networks can form electromagnetic interference shields with record shielding effectiveness of >60 dB in the microwave region at thicknesses <200 nm. High resolution patterns with line widths down to 10 µm are also printed using an aerosol‐jet printer which, when annealed at 200 °C, display conductivity >107 S m−1. Unlike conventional Ag‐nanoparticle inks, the 2D geometry of AgNS yields smooth, short‐free interfaces between electrode and active layer when used as the top electrode in vertical nanosheet heterostructures. This shows that all‐printed vertical heterostructures of AgNS/WS2/AgNS, where the top electrode is a mesh grid, function as photodetectors demonstrating that such structures can be used in optoelectronic applications that usually require transparent conductors.

Printing nanoparticle-based isotropic/anisotropic networks for directional electrical circuits

“…[10][11][12] Functional materials and structures with large sizes and fixed properties hardly meet the needs of integrated micro-devices. [13][14][15][16][17] The fine-pitch interconnect technology has become one of the important research areas for the microelectronics industry to meet the increasing demands of downsizing, functionalization, and integration. [18][19][20][21] Anisotropic materials can achieve different functions in different directions.…”

Solution processed, vertically stacked hetero-structured diodes based on liquid-exfoliated WS2 nanosheets: from electrode-limited to bulk-limited behavior

“…Two-dimensional (2D) materials have been extensively studied over the past two decades due to their diversity and range of interesting properties. 1,2 For example, focusing on electronic properties, silver nanosheets and MXenes are metallic, 3,4 graphene is a semimetal, 5 transition metal dichalcogenides such as tungsten disulfide (WS 2 ), are semiconducting 6 while boron nitride (BN) is an insulator. 7 This electronic diversity is very exciting as it means that different 2D materials can be used as different parts of electronic devices.…”

“…10,11 Such nanosheet dispersions can be used as inks and processed into thin films which, at the nanoscale, consist of disordered networks of nanosheets. 3,7,8,12 To date, many printing and solution-deposition methods have been used in this way, including ink-jet printing, 13,14 spincoating, 15 electrophoretic deposition, 16 spray coating. 7 In particular, spray coating is a method which is relatively versatile and is able to efficiently fabricate large-area networks on various types of substrates.…”

“…12 This makes it difficult to prepare stacked devices and means relatively few of these have been reported in the literature. To date, a small number of vertically-stacked printed or solutiondeposited devices, including capacitors, 7,21,22 memristors, 23,24 and photodetectors, 3,25,26 have been reported which combine LPE nanosheets and solution-processed top electrodes. Avoiding shorts is usually achieved by using thick semiconducting layers, 12 often with negative impacts on performance.…”

Confined growth of Ag nanoflakes induced by LSPR-driven carrier transfer in periodic nanopatterned arrays

“…Noble metal nanostructures are widely used in biosensors, plasmon-mediated chemical reactions (PMCRs), and other fields 1,2 due to their unique properties of surface plasmons and the collective oscillation of conducting electrons excited by incident electromagnetic fields. [3][4][5][6][7] The resonantly excited surface plasmons decay radiatively or non-radiatively and are generally unstable. Radiative relaxation has developed numerous surface-enhanced spectroscopic techniques, such as Raman spectroscopy and fluorescence spectroscopy, due to its characteristics of causing local electric fields and light scattering around nanostructures.…”