Stretchable and Transparent Organic Semiconducting Thin Film with Conjugated Polymer Nanowires Embedded in an Elastomeric Matrix

Abstract

easy processability. [8][9][10][11][12][13][14][15][16] Flexible organic transistors are usually fabricated on thin fl exible polymeric substrates. [17][18][19][20][21] They show good fl exibility with small bending radius of a few hundreds of micrometers. Although bending stability is important for large-area electronics in smart applications, it is still insuffi cient in itself to realize human-friendly electronic devices. Such devices require integration with curvilinear surfaces or fl exible and stretchable surfaces. [ 1,22 ] Device elasticity under tensile stress, i.e., stretchability, beyond fl exibility and bendability, is additionally required in a wide range of future electronic applications.Over the past few years, considerable research efforts have been applied to the development of stretchable electronics. Stretchable electronics are typically achieved through two approaches: geometrically structuring conventional brittle materials to have wavy or mesh forms, [ 3,23 ] or using of elastic conductive interconnections to integrate rigid circuit elements. [ 24,25 ] These are based on the strategy that the active material is not to be subjected to signifi cant deformations, and the overall electronic devices can be stretchable. However, these approaches unfortunately limit the fabrication of high-density integrated circuits. Because the interconnections of the wavy or mesh structures and the elastomeric composite are bulky, the distance between unit devices is limited to be reduced. Moreover, structuring whole devices using a buckling process is diffi cult during device miniaturization, and the methods require complex and expensive processing steps for the fabrication of wavy and mesh geo metries. For these reasons, stretchable electronic devices, which consist solely of intrinsically stretchable materials, need to be developed as the ultimate concept device. The development of intrinsically stretchable electronic materials faces several challenges, particularly in the development of stretchable active materials that can retain their electronic semiconducting properties under tensile stress. [26][27][28] Here, we describe the development of an intrinsically stretchable and transparent organic semiconducting material for use in stretchable organic thin fi lm transistors (OTFTs). The stretchable and transparent active material was designed to have the structure of 1D organic semiconducting Despite the considerable efforts applied toward developing stretchable electronics, few intrinsically stretchable semiconductors have been reported that retain the original electrical characteristics under stretching. This study introduces an intrinsically stretchable and transparent organic semiconducting layer by blending self-assembled nanowires (NWs) of an organic semiconductor with an elastomeric and transparent polymer. Blends of poly(3-hexylthio phene) (P3HT) NWs and poly(dimethylsiloxane) (PDMS) yield P3HT NW networks embedded in the PDMS matrix. Interestingly, it is found that the vertical distribution of P3HT NWs...

Recent Progress on Stretchable Electronic Devices with Intrinsically Stretchable Components

“…Therefore, the development of intrinsically stretchable semiconductor materials requires more investigation because such materials may provide deformability of the whole device and allow improvement in the integrity of the stacked layers in stretchable devices. There are two approaches to obtain stretchable semiconductor materials: synthesis of mole­ cularly stretchable materials and blending of polymeric or nanoscale semiconductors into an elastic polymer . The performance of stretchable semiconductor materials is summarized in Table 3 .…”

Structure and design of polymers for durable, stretchable organic electronics

“…However, when stretched above 50% strain, the composite showed better properties than strained pure nanowires. 135 The maintained field-effect mobility of the composite at high strains can be attributed to greater freedom of motion for the nanowires inside the PDMS matrix rather than in the pure nanowire crystal superstructure, allowing rotation of the wires, dissipating strain.…”

Significantly Increasing the Ductility of High Performance Polymer Semiconductors through Polymer Blending

“…14 In a recent report, P3HT fibrils were embedded into an elastomer host resulting in highly stretchable composite, although with a drop in mobility compared to the fibril network in an unstrained state. 15 …”

“…The increase in ductility is key to realizing physically robust flexible and stretchable devices. 15,17–19, In particular, retaining similar performance under large strains is a powerful screening tool to asses the suitability of a material for stretchable device applications. 20,21 These results highlight a design approach capable of achieving high mobility and highly ductile polymer semiconductor films.…”