Designable Integration of Silicide Nanowire Springs as Ultra‐Compact and Stretchable Electronic Interconnections

Abstract

Stretchable electronics are finding widespread applications in bio‐sensing, skin‐mimetic electronics, and flexible displays, where high‐density integration of elastic and durable interconnections is a key capability. Instead of forming a randomly crossed nanowire (NW) network, here, a large‐scale and precise integration of highly conductive nickel silicide nanospring (SiNix‐NS) arrays are demonstrated, which are fabricated out of an in‐plane solid–liquid–solid guided growth of planar Si nanowires (SiNWs), and subsequent alloy‐forming process that boosts the channel conductivity over 4 orders of magnitude (to 2 × 104 S cm−1). Thanks to the narrow diameter of the serpentine SiNix‐NS channels, the elastic geometry engineering can be accomplished within a very short interconnection distance (down to ≈3 µm), which is crucial for integrating high‐density displays or logic units in a rigid‐island and elastic‐interconnection configuration. Deployed over soft polydimethylsiloxane thin film substrate, the SiNix‐NS array demonstrates an excellent stretchability that can sustain up to 50% stretching and for 10 000 cycles (at 15%). This approach paves the way to integrate high‐density inorganic electronics and interconnections for high‐performance health monitoring, displays, and on‐skin electronic applications, based on the mature and rather reliable Si thin film technology.

Highly Stretchable High‐Performance Silicon Nanowire Field Effect Transistors Integrated on Elastomer Substrates

“…Finally, in view of achieving a scalable device integration upon soft thin film substrates, the discrete SiNW‐FET/island units can be interconnected by conductive and elastic organic/polymeric materials, [ 50 , 51 ] or by adopting highly conductive and more stable alloyed silicide NWs springs. [ 52 ] The latter is particularly suitable for realizing a high‐density integration of discrete logic or LED units upon elastomer substrate. Furthermore, the semiconducting SiNW channels, by themselves, could also be engineered into elastic spring forms and transferred directly onto PDMS substrate for device fabrication, [ 34 ] similar to the stretchable wavy c‐Si sheets, [ 53 ] ultra‐long Si nanoribbons [ 54 , 55 ] and ultra‐long SiNWs, [ 23 , 56 ] which represent a promising avenue to accomplish fully stretchable and durable high‐performance soft electronics, based on the mature c‐Si technology.…”

Orthogonal‐Stacking Integration of Highly Conductive Silicide Nanowire Network as Flexible and Transparent Thin Films

“…Slightly lower than the conductivity of SiNi alloy NW array reported in the literature (2 × 10 4 S cm) −1 . [36] Furthermore, a piece of SiNi-NS network, with length and width of 1 and 2 cm respectively, was used as flexible conductive electrode to drive 3 LED units, as diagrammed in Figure 3d, assembled upon PI substrate and fixed by silver paste. Under 2 V bias, three LED chips can be easily ignited with passing current of 0.1 mA.…”

Achieving High Performance Stretchable Conjugated Polymers via Donor Structure Engineering

“…[7] Their stretchability has been further enhanced through molecular design, [8][9][10] geometric engineering, and physical blending strategies to achieve harmonious humancomputer interactions. [11][12][13][14][15] Nevertheless, the complex process of geometric engineering and inferior mobility of the non-conjugated materials used in blending methods leads to the molecular design strategy being more competitive. Molecular design strategies are advantageous in terms of substantial tunability.…”