Morphological considerations of organic electronic films for flexible and stretchable devices

In the development of high-performance organic electronics, there has been significant effort in establishing relationships between microstructure and electronic properties, which has provided a deeper understanding of device operation and has guided performance improvements. When considering flexible and stretchable organic electronics, the mechanical behavior of the active layers becomes a critical attribute alongside electronic functionality. Thus, there is a need to establish the role of film morphology on both electronic properties and thermomechanical behavior, and the relationship between mechanical and electronic properties. In this article, we highlight recent advances in establishing these important relationships and the approaches employed to manage film morphology to optimize both mechanical behavior and device performance. Additionally, in stretchable applications, the film morphology may not be static, and capturing the microstructure changes under deformation is necessary to establish structure–property relationships over the expected physical operating space. Thus, also discuss film morphology change under large deformation for various stretchable film approaches.

[1]  Timothy O'Connor,et al.  Plasticization of PEDOT:PSS by Common Additives for Mechanically Robust Organic Solar Cells and Wearable Sensors , 2015 .

[2]  René A. J. Janssen,et al.  Tough, Semiconducting Polyethylene‐poly(3‐hexylthiophene) Diblock Copolymers , 2007 .

[3]  Zhenan Bao,et al.  Highly Conductive and Transparent PEDOT:PSS Films with a Fluorosurfactant for Stretchable and Flexible Transparent Electrodes , 2012 .

[4]  F. Krebs,et al.  Mechanical Properties of a Library of Low-Band-Gap Polymers , 2016 .

[5]  Zhenan Bao,et al.  Toward mechanically robust and intrinsically stretchable organic solar cells: Evolution of photovoltaic properties with tensile strain , 2012 .

[6]  Hyun Ho Choi,et al.  Stretchable and Transparent Organic Semiconducting Thin Film with Conjugated Polymer Nanowires Embedded in an Elastomeric Matrix , 2016 .

[7]  Frederik C. Krebs,et al.  Interlayer adhesion in roll-to-roll processed flexible inverted polymer solar cells , 2012 .

[8]  Darren J. Lipomi,et al.  Viability of stretchable poly(3-heptylthiophene) (P3HpT) for organic solar cells and field-effect transistors , 2015 .

[9]  Eric J. Sawyer,et al.  Mechanical degradation and stability of organic solar cells: molecular and microstructural determinants , 2015 .

[10]  R. Ghaffari,et al.  Recent Advances in Flexible and Stretchable Bio‐Electronic Devices Integrated with Nanomaterials , 2016, Advanced materials.

[11]  Benjamin C. K. Tee,et al.  Electronic Properties of Transparent Conductive Films of PEDOT:PSS on Stretchable Substrates , 2012 .

[12]  Darren J. Lipomi,et al.  Best of Both Worlds: Conjugated Polymers Exhibiting Good Photovoltaic Behavior and High Tensile Elasticity , 2014 .

[13]  Kwanghee Lee,et al.  Tensile drawing induced symmetry in poly(p-phenylene vinylene) films☆ , 2000 .

[14]  Bryan D. Vogt,et al.  Elastic Moduli of Ultrathin Amorphous Polymer Films , 2006 .

[15]  Christopher Bruner,et al.  Role of Molecular Weight on the Mechanical Device Properties of Organic Polymer Solar Cells , 2014 .

[16]  Samuel E. Root,et al.  Predicting the Mechanical Properties of Organic Semiconductors Using Coarse-Grained Molecular Dynamics Simulations , 2016 .

[17]  Daniel A. Fischer,et al.  Charge Transport in Highly Face-On Poly(3-hexylthiophene) Films , 2013 .

[18]  Zhenan Bao,et al.  A Rapid and Facile Soft Contact Lamination Method: Evaluation of Polymer Semiconductors for Stretchable Transistors , 2014 .

[19]  D. Lipomi Stretchable Figures of Merit in Deformable Electronics , 2016, Advanced materials.

[20]  R. J. Kline,et al.  Significantly Increasing the Ductility of High Performance Polymer Semiconductors through Polymer Blending. , 2016, ACS Applied Materials and Interfaces.

[21]  Hongbo Lu,et al.  An ABA triblock copolymer strategy for intrinsically stretchable semiconductors , 2015 .

[22]  Daniel J. Burke,et al.  Mechanical Properties of Conjugated Polymers and Polymer‐Fullerene Composites as a Function of Molecular Structure , 2014 .

[23]  Raja Shahid Ashraf,et al.  Exploring the origin of high optical absorption in conjugated polymers. , 2016, Nature materials.

[24]  I. Hansen,et al.  Substrate specificity and transport mechanism of amino-acid transceptor Slimfast from Aedes aegypti , 2015, Nature Communications.

[25]  Martin Heeney,et al.  Correlations between mechanical and electrical properties of polythiophenes. , 2010, ACS nano.

[26]  Daniel J. Burke,et al.  Increased elasticity of a low-bandgap conjugated copolymer by random segmentation for mechanically robust solar cells , 2014 .

[27]  Zhenan Bao,et al.  Inducing Elasticity through Oligo‐Siloxane Crosslinks for Intrinsically Stretchable Semiconducting Polymers , 2016 .

[28]  Adam D. Printz,et al.  Yield Point of Semiconducting Polymer Films on Stretchable Substrates Determined by Onset of Buckling. , 2015, ACS applied materials & interfaces.

[29]  Lee J. Richter,et al.  Anisotropic Structure and Charge Transport in Highly Strain‐Aligned Regioregular Poly(3‐hexylthiophene) , 2011 .

[30]  Christopher M. Proctor,et al.  Mechanical Properties of Solution-Processed Small-Molecule Semiconductor Films. , 2016, ACS applied materials & interfaces.

[31]  Gang Li,et al.  For the Bright Future—Bulk Heterojunction Polymer Solar Cells with Power Conversion Efficiency of 7.4% , 2010, Advanced materials.

[32]  Timothy O'Connor,et al.  Molecularly Stretchable Electronics , 2014 .

[33]  David Beljonne,et al.  Approaching disorder-free transport in high-mobility conjugated polymers , 2014, Nature.

[34]  Jean-Luc Brédas,et al.  Entanglements in P3HT and their influence on thin-film mechanical properties: Insights from molecular dynamics simulations , 2015 .

[35]  Zhenan Bao,et al.  Organic Semiconductor Growth and Morphology Considerations for Organic Thin‐Film Transistors , 2010, Advanced materials.

[36]  R. J. Kline,et al.  Morphological Origin of Charge Transport Anisotropy in Aligned Polythiophene Thin Films , 2014 .

[37]  Joon Hak Oh,et al.  Tuning Mechanical and Optoelectrical Properties of Poly(3-hexylthiophene) through Systematic Regioregularity Control , 2015 .

[38]  E. Reichmanis,et al.  Elastomer-Polymer Semiconductor Blends for High-Performance Stretchable Charge Transport Networks , 2016 .

[39]  H. Sirringhaus 25th Anniversary Article: Organic Field-Effect Transistors: The Path Beyond Amorphous Silicon , 2014, Advanced materials.

[40]  Hee Taek Yi,et al.  Ultra-flexible solution-processed organic field-effect transistors , 2012, Nature Communications.

[41]  John A Rogers,et al.  Stretchable, Curvilinear Electronics Based on Inorganic Materials , 2010, Advanced materials.

[42]  R. J. Kline,et al.  Molecular Characterization of Organic Electronic Films , 2011, Advanced materials.

[43]  Xiaodan Gu,et al.  Intrinsically stretchable and healable semiconducting polymer for organic transistors , 2016, Nature.

[44]  Xiaodong Chen,et al.  Stretchable Organic Semiconductor Devices , 2016, Advanced materials.

[45]  R. J. Kline,et al.  Anisotropic Elastic Modulus of Oriented Regioregular Poly(3-hexylthiophene) Films , 2016 .

[46]  J. Moulton,et al.  Gel processing of electrically conductive blends of poly(3‐octylthiophene) and ultrahigh molecular weight polyethylene , 1992 .

[47]  Timothy O'Connor,et al.  Stretching and conformal bonding of organic solar cells to hemispherical surfaces , 2014 .

[48]  O. Awartani,et al.  Microstructural behavior and failure mechanisms of organic semicrystalline thin film blends , 2016 .

[49]  R. Dauskardt,et al.  Molecular-Scale Understanding of Cohesion and Fracture in P3HT:Fullerene Blends. , 2015, ACS applied materials & interfaces.

[50]  Peter J. Diemer,et al.  Oriented Liquid Crystalline Polymer Semiconductor Films with Large Ordered Domains. , 2015, ACS applied materials & interfaces.

[51]  Unyong Jeong,et al.  Conducting Polymer Dough for Deformable Electronics , 2016, Advanced materials.

[52]  Bethany I Lemanski,et al.  Correlating Stiffness, Ductility, and Morphology of Polymer:Fullerene Films for Solar Cell Applications , 2013 .

[53]  C. Keplinger,et al.  25th Anniversary Article: A Soft Future: From Robots and Sensor Skin to Energy Harvesters , 2013, Advanced materials.

[54]  Zhenan Bao,et al.  Highly Stretchable Transistors Using a Microcracked Organic Semiconductor , 2014, Advanced materials.

[55]  Kyung‐Eun Byun,et al.  Polythiophene Nanofibril Bundles Surface‐Embedded in Elastomer: A Route to a Highly Stretchable Active Channel Layer , 2015, Advanced materials.