Organic semiconductor

About: Organic semiconductor is a research topic. Over the lifetime, 15905 publications have been published within this topic receiving 533881 citations.

Evidence for exciton confinement in crystalline organic multiple quantum wells.

Abstract: Multiple-quantum-well structures based on two crystalline organic semiconductors, namely, 3,4,9,10 perylenetetracarboxylic dianhydride and 3,4,7,8 naphthalenetetracarboxylic dianhydride, have been grown by organic molecular-beam deposition. Both optical-absorption and time-resolved photoluminescence measurements reveal a significant effect on the binding energy and the radiative recombination probability of excitons due to localization of carriers. Variational calculations of the ground-state exciton energy in quantum wells have been done, and the results agree with the experimental data. This provides evidence for exciton confinement in organic quantum-well structures.

Electrical Scanning Probe Microscopy on Active Organic Electronic Devices

Abstract: Polymer- and small-molecule-based organic electronic devices are being developed for applications including electroluminescent displays, transistors, and solar cells due to the promise of low-cost manufacturing. It has become clear that these materials exhibit nanoscale heterogeneities in their optical and electrical properties that affect device performance, and that this nanoscale structure varies as a function of film processing and device-fabrication conditions. Thus, there is a need for high-resolution measurements that directly correlate both electronic and optical properties with local film structure in organic semiconductor films. In this article, we highlight the use of electrical scanning probe microscopy techniques, such as conductive atomic force microscopy (c-AFM), electrostatic force microscopy (EFM), scanning Kelvin probe microscopy (SKPM), and similar variants to elucidate charge injection/extraction, transport, trapping, and generation/recombination in organic devices. We discuss the use of these tools to probe device structures ranging from light-emitting diodes (LEDs) and thin-film transistors (TFT), to light-emitting electrochemical cells (LECs) and organic photovoltaics.

Potential for spin-based information processing in a thin-film molecular semiconductor

Abstract: Spintronics devices, which exploit the intrinsic spin of electrons as well as their charge, require precise control and read-out of electron spins. For organic semiconductors to find use in spintronic applications, it is desirable to identify molecules that possess long spin relaxation times. This paper establishes that copper phthalocyanine, a blue pigment commonly used in paints and dyes, appears to satisfy this requirement. It is inexpensive and can be easily processed into a thin-film form of the type used for device fabrication, making it a candidate material system for spin-based quantum information processing and other spintronic applications.

Correlations between Mechanical and Electrical Properties of Polythiophenes

Abstract: The elastic moduli of polythiophenes, regioregular poly(3-hexylthiophene) (P3HT) and poly-(2,5-bis(3-alkylthiophene-2-yl)thieno[3,2-b]thiophene) (pBTTT), are compared to their field effect mobility showing a proportional trend. The elastic moduli of the films are measured using a buckling-based metrology, and the mobility is determined from the electrical characteristics of bottom contact thin film transistors. Moreover, the crack onset strain of pBTTT films is shown to be less than 2.5%, whereas that of P3HT is greater than 150%. These results show that increased long-range order in polythiophene semiconductors, which is generally thought to be essential for improved charge mobility, can also stiffen and enbrittle the film. This work highlights the critical role of quantitative mechanical property measurements in guiding the development of flexible organic semiconductors.

Unconventional, chemically stable, and soluble two-dimensional angular polycyclic aromatic hydrocarbons: from molecular design to device applications.

Abstract: ConspectusPolycyclic aromatic hydrocarbons (PAHs), consisting of laterally fused benzene rings, are among the most widely studied small-molecule organic semiconductors, with potential applications in organic field-effect transistors (OFETs) and organic photovoltaics (OPVs). Linear acenes, including tetracene, pentacene, and their derivatives, have received particular attention due to the synthetic flexibility in tuning their chemical structure and properties and to their high device performance. Unfortunately, longer acenes, which could exhibit even better performance, are susceptible to oxidation, photodegradation, and, in solar cells which contain fullerenes, Diels–Alder reactions. This Account highlights recent advances in the molecular design of two-dimensional (2-D) PAHs that combine device performance with environmental stability.New synthetic techniques have been developed to create stable PAHs that extend conjugation in two dimensions. The stability of these novel compounds is consistent with Clar...