A broad organic–inorganic series of hybrid metal iodide perovskites with the general formulation AMI3, where A is the methylammonium (CH3NH3+) or formamidinium (HC(NH2)2+) cation and M is Sn (1 and 2) or Pb (3 and 4) are reported. The compounds have been prepared through a variety of synthetic approaches, and the nature of the resulting materials is discussed in terms of their thermal stability and optical and electronic properties. We find that the chemical and physical properties of these materials strongly depend on the preparation method. Single crystal X-ray diffraction analysis of 1–4 classifies the compounds in the perovskite structural family. Structural phase transitions were observed and investigated by temperature-dependent single crystal X-ray diffraction in the 100–400 K range. The charge transport properties of the materials are discussed in conjunction with diffuse reflectance studies in the mid-IR region that display characteristic absorption features. Temperature-dependent studies show a ...

Semiconducting tin and lead iodide perovskites with organic cations: phase transitions, high mobilities, and near-infrared photoluminescent properties.

Since the discovery of highly conducting polyacetylene by Shirakawa, MacDiarmid, and Heeger in 1977, π-conjugated systems have attracted much attention as futuristic materials for the development and production of the next generation of electronics, that is, organic electronics. Conceptually, organic electronics are quite different from conventional inorganic solid state electronics because the structural versatility of organic semiconductors allows for the incorporation of functionality by molecular design. This versatility leads to a new era in the design of electronic devices. To date, the great number of π-conjugated semiconducting materials that have either been discovered or synthesized generate an exciting library of π-conjugated systems for use in organic electronics. 11 However, some key challenges for further advancement remain: the low mobility and stability of organic semiconductors, the lack of knowledge regarding structure property relationships for understanding the fundamental chemical aspects behind the structural design, and realization of desired properties. Organic field-effect transistors (OFETs) are a kind of device consisting of an organic semiconducting layer, a gate insulator layer, and three terminals (drain, source, and gate electrodes). OFETs are not only essential building blocks for the next generation of cheap and flexible organic circuits, but they also provide an important insight into the charge transport of πconjugated systems. Therefore, they act as strong tools for the exploration of the structure property relationships of πconjugated systems, such as parameters of field-effect mobility (μ, the drift velocity of carriers under unit electric field), current on/off ratio (the ratio of the maximum on-state current to the minimum off-state current), and threshold voltage (the minimum gate voltage that is required to turn on the transistor). 17 Since the discovery of OFETs in the 1980s, they have attracted much attention. Research onOFETs includes the discovery, design, and synthesis of π-conjugated systems for OFETs, device optimization, development of applications in radio frequency identification (RFID) tags, flexible displays, electronic papers, sensors, and so forth. It is beyond the scope of this review to cover all aspects of π-conjugated systems; hence, our focus will be on the performance analysis of π-conjugated systems in OFETs. This should make it possible to extract information regarding the fundamental merit of semiconducting π-conjugated materials and capture what is needed for newmaterials and what is the synthesis orientation of newπ-conjugated systems. In fact, for a new science with many practical applications, the field of organic electronics is progressing extremely rapidly. For example, using “organic field effect transistor” or “organic field effect transistors” as the query keywords to search the Web of Science citation database, it is possible to show the distribution of papers over recent years as shown in Figure 1A. It is very clear

Semiconducting π-conjugated systems in field-effect transistors: a material odyssey of organic electronics.

Electron and ambipolar transport in organic field-effect transistors.

Organic electron-transporting materials are essential for the fabrication of organic p-n junctions, photovoltaic cells, n-channel field-effect transistors, and complementary logic circuits. Rylene diimides are a robust, versatile class of polycyclic aromatic electron-transport materials with excellent thermal and oxidative stability, high electron affinities, and, in many cases, high electron mobilities; they are, therefore, promising candidates for a variety of organic electronics applications. In this review, recent developments in the area of high-electron-mobility diimides based on rylenes and related aromatic cores, particularly perylene- and naphthalene-diimide-based small molecules and polymers, for application in high-performance organic field-effect transistors and photovoltaic cells are summarized and analyzed.

Rylene and related diimides for organic electronics.

The present invention provides a heterocyclic compound and an organic light-emitting device including the heterocyclic compound. The organic light-emitting devices using the heterocyclic compounds have high-efficiency, low driving voltage, high luminance and long lifespan.

Organic light-emitting device

The authors demonstrated that N,N′-ditridecyl-3,4,9,10-perylenetetracarboxylic diimide (PTCDI-C13) thin-film transistors (TFTs) exhibited high field-effect electron mobility of 2.1cm2∕Vs by just annealing at an adequate temperature (140°C) after the TFT fabrications. While PTCDI-C13 formed c-axis oriented thin films, the thermal treatments improved crystallinity of the thin films as revealed by x-ray diffraction. The thermal treatment also affected thin-film morphologies; the morphologies changed from oval ball-like grains to flat and large tilelike grains, which had molecular height steps and whose size reached several micrometers.

High mobility n-type thin-film transistors based on N,N′-ditridecyl perylene diimide with thermal treatments

/pdf/improved-crystal-growth-and-emission-gain-narrowing-of-57jdk12dyr.pdf

Improved Crystal‐Growth and Emission Gain‐Narrowing of Thiophene/Phenylene Co‐Oligomers

[**] This work was supported by the Cooperative Link for Unique Science and Technology for Economy Revitalization (CLUSTER) of Japan’s Ministry of Education, Culture, Sports, Science and Technology. It was also supported by the New Energy and Industrial Technology Development Organization (NEDO), in the area of Organic Materials Technology for Solid-State Injection Laser application, and by the Ministry’s 21st Century COE program.

/pdf/laser-oscillation-in-monolithic-molecular-single-crystals-1f6e2wzmcw.pdf

Laser oscillation in monolithic molecular single crystals

We have determined crystallographic structures of four thiophene/phenylene co-oligomers with different molecular shapes. The compounds consist of the molecules straight, bent, or zigzag. All the crystals are monoclinic with space group either P21/c or P21/n, Z = 4, and the unique axis of b. The crystals are characterized by the presence of the molecular layered structure in which the molecules form the well-known herringbone structure laterally spreading along the ab-plane. We investigate the molecular disposition in the crystals and present its peculiarity in relation to those comprising nonstraight molecules (e.g., bent or zigzag). The specific effects upon optical characteristics produced by this peculiarity are mentioned.

crystal structures of thiophene/phenylene co-oligomers with different molecular shapes

/pdf/organic-field-effect-transistors-made-of-epitaxially-grown-qmoa0do04s.pdf

Musubu Ichikawa

Papers

High mobility n-type thin-film transistors based on N,N′-ditridecyl perylene diimide with thermal treatments

Improved Crystal‐Growth and Emission Gain‐Narrowing of Thiophene/Phenylene Co‐Oligomers

Laser oscillation in monolithic molecular single crystals

crystal structures of thiophene/phenylene co-oligomers with different molecular shapes

Organic Field-Effect Transistors Made of Epitaxially Grown Crystals of a Thiophene/Phenylene Co-oligomer