Metal phthalocyanines (MPcs) are versatile conjugated macrocycles that have attracted a great deal of interest as active components in modern organic electronic devices. In particular, the charge transport properties of MPcs, their chemical stability, and their synthetic versatility make them ideal candidate materials for use in organic thin-film transistors (OTFTs). This article reviews recent progress in both the material design and device engineering of MPc-based OTFTs, including the introduction of solubilizing groups on the MPcs and the surface modification of substrates to induce favorable MPc self-assembly. Finally, a discussion on emerging niche applications based on MPc OTFTs will be explored, in addition to a perspective and outlook on these promising materials in OTFTs. The scope of this review is focused primarily on the advances made in the field of MPc-based OTFTs since 2008.

Phthalocyanine-Based Organic Thin-Film Transistors: A Review of Recent Advances

(i) R. W. Walker: Some burning problems in combustion chemistry (68 pp.). The major features of this article are the initiation steps for alkanes, alkenes, aromatics, and aldehydes, the reactions of O, with ethyl radicals, and the formation of aromatics, polycyclic aromatics, and soot by cyclisation reactions of reactive intermediates, especially allyl and propargyl type radicals. A lot of actual kinetic data are given and dicussed in detail. (ii) J. L. Durant Jr.: Reactions of NH„ species (47 pp.). The chemistry of NH, species contains a wide variety of processes ranging from very low temperatures in the troposphere up to NO, formation at very high temperatures in combustion processes. Therefore, several reviews have been published in the past. The present review is focused on reactions of NH and NH2 with O, 02 and NO from a theoretical point of view. The thermochemistry, potential energy surfaces, including different electronic states, reaction paths, and the dynamics of some selected processes are discussed in a compact manner. (iii) S. M. Pimblott, N. J. B. Green: Recent advances in the kinetics of radiolytic processes (58 pp.). The main topics are theoretical models for the energy loss (LET) of the radiation, the distribution of ionization and excitation processes, followed by chemical reactions in the spurs and later at the time scale the transition from an inhomogeneous to the homoge-

Surfaces and Interfaces of Solid Materials

A fiber-shaped organic photovoltaic cell is demonstrated, utilizing concentric thin films of small molecular organic compounds. Illuminated at normal incidence to the fiber axis through a thin metal electrode, the cell exhibits 0.5% power conversion efficiency, compared to 0.76% for a planar control device. The fiber device efficiency is nearly independent of illumination angle, increasing its power generation over the planar counterpart for diffuse illumination. Losses due to partial shading of the fiber surface are minimal, while the coated fiber length is limited only by the experimental deposition chamber geometry—factors favoring scale-up to woven energy harvesting textiles.

Fiber based organic photovoltaic devices

2-Mercaptobenzimidazole as a copper corrosion inhibitor: Part II. Surface analysis using X-ray photoelectron spectroscopy

Effects of substrate temperature on copper(II) phthalocyanine thin films

Influence of substrate doping on the surface chemistry and morphology of Copper Phthalocyanine ultra thin films on Si (111) substrates

The presence of occupied intra-band gap states in oxygen-deficient tin dioxide (SnOx; 1 < x < 2) is crucial for efficient manufacturing of multipurpose electronic devices based on transparent conducting oxides. Former experimental determination of these states was conducted for well-defined, usually thick tin oxides obtained under highly controlled vacuum conditions. In this work, we present precise specification of gap defects states for ultra-thin SnOx layers prepared by sol-gel synthesis followed with spin-coat deposition. Post-deposition drying and annealing processing changed layers’ surface morphology and bulk crystalline structure as monitored by scanning electron microscopy, atomic force microscopy and x-ray diffraction. An x-ray photoemission spectroscopy (XPS) analysis of chemical composition revealed the presence of both Sn2+ and Sn4+ species in layers with and without post-drying annealing step. A stronger contribution of SnO was found for dried SnOx. In the valence band region, XPS studies revealed pronounced O 2p and hybridised Sn 5p/5s–O 2p states as well as deep, overlapping with the O 2p, band gap states resulting from Sn 5s orbitals. These states— attributed to defect states—indicated enhanced presence of Sn2+ cations, and were assigned to ‘bridging’ oxygen vacancies. Complementary photoemission yield spectroscopy (PYS) studies of the SnOx band gap region revealed an increased effective density of occupied electronic states below the Fermi level EF for annealed layers. The consequence was a work function reduction by 0.15 eV after the annealing process. PYS results allowed a precise detection of SnOx shallow band gap states close to EF. These states were attributed to surface oxygen vacancies, which was confirmed by computer modelling. Finally, the annealed layers exhibited higher calculated charge carrier concentration, hence the increased n-type character.

https://iopscience.iop.org/article/10.1088/1361-6463/aacf3a/pdf

Detection of intra-band gap defects states in spin-coated sol-gel SnOx nanolayers by photoelectron spectroscopies

Comparative study of surface morphology of copper phthalocyanine ultra thin films deposited on Si (111) native and RCA-cleaned substrates

X-ray Photoelectron Spectroscopy characterization of native and RCA-treated Si (111) substrates and their influence on surface chemistry of copper phthalocyanine thin films

Lucyna Grządziel

Papers

Influence of substrate doping on the surface chemistry and morphology of Copper Phthalocyanine ultra thin films on Si (111) substrates

Detection of intra-band gap defects states in spin-coated sol-gel SnOx nanolayers by photoelectron spectroscopies

Comparative study of surface morphology of copper phthalocyanine ultra thin films deposited on Si (111) native and RCA-cleaned substrates

X-ray Photoelectron Spectroscopy characterization of native and RCA-treated Si (111) substrates and their influence on surface chemistry of copper phthalocyanine thin films

Energy level alignment at the Si(111)/RCA-SiO2/copper(II) phthalocyanine ultra-thin film interface