We investigate the electrical characteristics of top-contact pentacene thin-film transistors (TFTs) fabricated with various thicknesses of the Au source and the drain (S/D) electrodes, i.e., 20, 30, 50, 70, and 105 nm. Pentacene TFTs exhibit enhancements in the drain current and the fieldeffect mobility with increasing thickness of Au S/D electrodes up to 50 nm, after which the TFT performance ...

In the field of molecular electronics, thin films of molecules adsorbed on insulating surfaces are used as the functional building blocks of electronic devices. Control of the structural and electronic properties of the thin films is required for reliably operating devices. Here, noncontact atomic force and Kelvin probe force microscopies have been used to investigate the growth and electrostat...

Organic/inorganic interfaces play a crucial role in flexible electronic devices such as organic field effect transistors (OFETs), organic light emitting diodes (OLEDs) and organic photovoltaics (OPVs). Charge injection and transport through the interface is not only important in understanding devices, but also a primary challenge in developing and optimizing devices. More flexibility in fabrica...

Cylindrical vector beams, such as radially or azimuthally polarized doughnut beams, are combined with topography studies of pentacene thin films, allowing us to correlate Raman spectroscopy with intermolecular interactions depending on the particular pentacene polymorph. Polarization-dependent Raman spectra of the C-H bending vibrations are resolved layer by layer within a thin film of ∼20 nm t...

Functionalization of the pro-cata positions of pentacene with groups held perpendicular to the aromatic plane, in this case through a rigid 1,3-dioxole unit, yields pentacene derivatives that are stable and soluble, and still maintain edge-to-face interactions in the solid state.

This report discusses some of the electrical and optical properties of thin films of the organic semiconductor pentacene fabricated using thermal evaporation. Conductivities of between 1.84 × 10 Ω cm and 7.49 × 10 Ω cm are reported. Transistors using thermally evaporated pentacene were fabricated and mobilities of up to 0.03 cmVs were obtained.

Introduction Organic thin-film transistors (TFT) have received considerable attention due to promises of low manufacturing costs, ease of processibility, and extendibility to flexible circuits. The feasibility of organic TFTs has largely been demonstrated with devices that use metal source and drain electrodes, such as gold and palladium. Such devices, when fabricated in the bottom-contact (BC)...

Thermal scanning lithography is used to pattern semiconducting nanoribbon-like pentacene structures with ultrahigh spatial resolution onto arbitrary substrates in air. The method allows control of the pentacene crystal growth direction and domain-size distribution. By combining these quasi-one-dimensional nanoribbon-like structures with conductive electrodes and a suitable gate dielectric, func...

In bulk heterojunction photovoltaic systems both the open-circuit voltage as well as the short-circuit current, and hence the power conversion efficiency, are dependent on the optical bandgap of the electron-donor material. While first-principles methods are computationally intensive, simpler model Hamiltonian approaches typically suffer from one or more flaws: inability to optimize the geometr...

Understanding the mechanism of singlet exciton fission, in which a singlet exciton separates into a pair of triplet excitons, is crucial to the development of new chromophores for efficient fission-sensitized solar cells. The challenge of controlling molecular packing and energy levels in the solid state precludes clear determination of the singlet fission pathway. Here, we circumvent this diff...