Recent advances in solid-state organic lasers

Organic solid-state lasers are reviewed, with a special emphasis on works published during the last decade. Referring originally to dyes in solid-state polymeric matrices, organic lasers also include the rich family of organic semiconductors, paced by the rapid development of organic light emitting diodes. Organic lasers are broadly tunable coherent sources are potentially compact, convenient and manufactured at low-costs. In this review, we describe the basic photophysics of the materials used as gain media in organic lasers with a specific look at the distinctive feature of dyes and semiconductors. We also outline the laser architectures used in state-of-the-art organic lasers and the performances of these devices with regard to output power, lifetime, and beam quality. A survey of the recent trends in the field is given, highlighting the latest developments in terms of wavelength coverage, wavelength agility, efficiency and compactness, or towards integrated low-cost sources, with a special focus on the great challenges remaining for achieving direct electrical pumping. Finally, we discuss the very recent demonstration of new kinds of organic lasers based on polaritons or surface plasmons, which open new and very promising routes in the field of organic nanophotonics

Reinventing Butyl Rubber for Stretchable Electronics

The development of stretchable electronic devices that are soft and conformable has relied heavily on a single material – polydimethylsiloxane – as the elastomeric substrate. Although polydimethylsiloxane has a number of advantageous characteristics, its high gas permeability is detrimental to stretchable devices that use materials sensitive to oxygen and water vapor, such as organic semiconductors and oxidizable metals. Failing to protect these materials from atmosphere-induced decomposition leads to premature device failure; therefore, it is imperative to develop elastomers with gas barrier properties that enable stretchable electronics with practical lifetimes. Here, we reinvent butyl rubber – a material with an intrinsically low gas permeability traditionally used in the innerliners of tires to maintain air pressure – for stretchable electronics. This new material is smooth and optically transparent, possesses the low gas permeability typical of butyl rubber, and vastly outperforms polydimethylsiloxane as an encapsulating barrier to prevent the atmospheric degradation of sensitive electronic materials and the premature failure of functioning organic devices. The merits of transparent butyl rubber presented here position this material as an important counterpart to polydimethylsiloxane that will enable future generation stretchable electronics

Metal salt-derived In-Ga-Zn-O semiconductors incorporating formamide as a novel co-solvent for producing solution-processed, electrohydrodynamic-jet printed, high performance oxide transistors

We report the previously unrecognized co-solvent, formamide (FA), which can comprehensively improve both the device performance and bias stability of metal salt-derived, solution-processed In-Ga-Zn-O (IGZO) TFTs. By incorporating FA in IGZO precursor solutions, the chemical structures are tailored adequately for reducing the content of hydroxide and encouraging the oxygen vacancy formation, which has not been fulfilled in conventional chemical/physical approaches. Owing to such distinct chemical structural evolution, the field-effect mobility is enhanced dramatically by a factor of 4.3 (from 2.4 to 10.4 cm2 V -1 s-1), and the threshold voltage shift during a positive-bias stress test is suppressed effectively by a factor of 2.3 (from 9.3 to 4.1 V) for unpassivated devices. The addition of formamide to IGZO precursor solutions also facilitates electrohydrodynamic-jet (e-jet) printability, with which the directly printed device with a channel width of ???30 ??m is demonstrated successfully. In addition, a high performance, solution-processed IGZO transistor with a mobility of 50 cm2 V-1 s -1 is suggested through coupling a FA-added IGZO oxide semiconductor with a solution-processed zirconium aluminum oxide ((Zr,Al)2O x) gate dielectric.close9

Split-gate organic field effect transistors: Control over charge injection and transport

A split-gate field effect transistor containing four electrodes, source, drain, two gates allows enhanced transport for specific carrier species and separate control of carrier polarity over two gate regimes. The device can be operated as a transistor or a diode by controlling gate biases