Organic Semiconductor/Insulator Polymer Blends for High-Performance Organic Transistors

Abstract

Abstract:We reviewed recent advances in high-performance organic field-effect transistors (OFETs) based on organic semiconductor/insulator polymer blends. Fundamental aspects of phase separation in binary blends are discussed with special attention to phase-separated microstructures. Strategies for constructing semiconductor, semiconductor/dielectric, or semiconductor/passivation layers in OFETs by blending organic semiconductors with an insulating polymer are discussed. Representative studies that utilized such blended films in the following categories are covered: vertical phase-separation, processing additives, embedded semiconductor nanowires.

Photoinduced Anisotropic Assembly of Conjugated Polymers in Insulating Polymer Blends

“…[30][31] The aggregates formed Phase-separation in polymer blend films depends on molecular (i.e., polymer solubility, miscibility of two polymers, surface energy of substrate, and volatility, viscosity, and surface tension of solvent), thermodynamic (i.e., composition, temperature, and pressure) and processing parameters (i.e., film deposition method). 6,8,27,32 In general, the effect of polymer solubility has been widely taken into account to understand the phase-separation of polymer blends during a spin-coating process. 27 In contrast to the blend films spin-coated from the untreated solutions, those obtained from UV irradiated solutions exhibit three apparently different parts, featureless, island-like, and nanofibrillar ( Figure 2a).…”

Inkjet‐Printing: A New Fabrication Technology for Organic Transistors

“…Inkjet‐printing of the gate dielectric is usually considered a very difficult step in the fabrication of thin film transistors, as the sequential printing of different layers requires the utilization of orthogonal solvents in order to avoid dissolution of the previously printed layers . This is especially true when considering the dielectric printing on the top of the organic semiconductor, as the two types of materials are often dissolved in the same solvents . Printing the gate dielectric on the top of the metallic gate is usually regarded as easier since the solvents used for the preparation of dielectric inks are not normally able to attack the underlying metallic layer.…”

“…The order by which these layers are deposited strongly influences the final performance of the transistor. Therefore, it is important to distinguish between the following structures: (i) bottom‐gate/bottom‐contact, (ii) bottom‐gate/top‐contact, (iii) top‐gate/bottom‐contact, and (iv) top‐gate/top‐contact. These structures, schematically shown in Figure , differ because of the position of the semiconducting layer with respect to the gate electrode and the source and drain contacts.…”

Thickness-dependent electrical properties of soluble acene–polymer blend semiconductors

“…Organic semiconductor/insulating polymer blends have proven to be ideal materials for optimizing the electrical properties of organic electronic devices such as organic field-effect transistors (OFETs) [1][2][3][4]. Because charge transport occurs at the dielectric/semiconductor interface laterally, the conducting pathway from the source to drain electrode should be well-defined.…”