Raman scattering gain in DOO-PPV films

Journal ArticleWe have investigated the optical emission characteristics of poly(2,5-dioctyloxy-p-phenylenevinylene) (DOO-PPV) thin films under high intensity ps pulsed laser excitation (Ipump > 1 MW/ cm2). We observed that the emission spectrum consist of a spectrally narrowed emission (SNE) band (FWHM ~ 10 nm) and superimposed sharp spectral lines. High resolution spectral measurements conducted at room and liquid nitrogen temperatures show that the spectral width of these lines is less than 1 nm. The lines peak positions are independent of film thickness, however, they shifts upon changing the excitation wavelength. Also, the excitation intensity dependence of these narrow lines is found to be different from that of the SNE band. We argue that the narrow lines are due to Raman scattering gain of the 1st, 2nd and 3d order Raman active modes of DOO-PPV

Solution-Processable Nanowire Field-Effect Transistors

Solution-processable single-crystalline inorganic semiconducting nanowires are excellent building blocks for printable electronics requiring high performance of semiconducting components. Excellent charge carrier mobilities of crystalline nanowires combined with solvent-based nanowire processing open up possibilities for low-cost nanowire electronics targeting a variety of applications ranging from flexible circuits to chemical and biological sensors. Nanowire field-effect transistors are key devices for most of such applications. Recent developments in controllable nanowire positioning and orientation on the substrates and electrical property selection provide the necessary technological breakthroughs enabling the fabrications of reproducible nanowire transistors. In this chapter, we discuss the nanowire assembly methods and high-spatial-resolution scanning probe microscopy techniques towards scalable fabrication of high-performance printable nanowire field-effect transistors

Amplified resonant Raman scattering in conducting polymer thin films

Journal ArticleUsing picosecond pulsed laser excitation, we investigate the optical emission characteristics of poly(2,5-dioctyloxy-p-phenylenevinylene), (DOO-PPV), thin films at high excitation intensities (~1-90 MW/cm2). We observe the presence of amplified resonance Raman scattering in the emission spectra of conducting polymer films. The effect results in sharp Raman lines (widths smaller than 3 Å) superimposed on a significantly broader, well known, spectrally narrowed emission band (width ~10 nm) caused by the amplified spontaneous emission in the waveguided polymer film. At the highest used excitation intensities, Raman scattering dominates the DOO-PPV emission spectrum resulting in a highly monochromatic, single-line emission spectrum

Laser action in polydialkylfluorene films: influence of low-temperature thermal treatment

Journal ArticleWe have used a variety of optical probes to investigate the changes occurring upon low-temperature thermal treatment to the emissive properties of dialkyl substituted polyfluorene thin films. We found that the low-temperature-driven morphological changes involving aggregates formation, which are observed in the absorption and photoluminescence spectra at low excitation intensities, give rise at high excitation intensities to laser action in the blue spectral range. In some cases, switching We have used a variety of optical probes to investigate the changes occurring upon low-temperature thermal treatment to the emissive properties of dialkyl substituted polyfluorene thin films. We found that the low-temperature-driven morphological changes involving aggregates formation, which are observed in the absorption and photoluminescence spectra at low excitation intensities, give rise at high excitation intensities to laser action in the blue spectral range. In some cases, switching between two stimulated emission bands was also observed. between two stimulated emission bands was also observed

Развитие внешнеторговых связей России в период царствования Михаила Федоровича Романова

The article is devoted to the evolution of the foreign trade relations of Russia during the reign of Mikhail Romanov (1613-1645). The author analyzes the routes of foreign trade, the range of export goods, social composition of the merchants, the changes of foreign trade geography. The special attention is paid to the impact of the Russian Orthodox Church in the development of foreign trade

Роль коренных народов Дальнего Востока в становлении и развитии российско-японской торговли в XVIII-XIX вв.

The author discusses the role of the indigenous peoples of the Far East (Ainu, Oroch, Nivkhi, Evenki, Udege, Negidals, etc.) in the development of trade between Russia and Japan. He identifi es the role of the indigenous population of the Far East as the mediators in Russo-Japanese trade, and argues that they played this role during the period when the trade between two states was not offi cially resolved. He also characterizes the range of goods, channels of their delivery and distribution, and specifi cs of barter exchange

Внешняя торговля стран Юго-Восточной Азии и торговые интересы России в XVIII-XIX вв.

The monograph is devoted to the history of foreign trade relations of the countries of South-East Asia during the XVIII–XIX centuries.Special attention is paid to the foreign trade interests of the Russian Empire in the region of East in the period under review.The text is illustrated with pre-revolutionary photographs and drawings extracted from domestic and foreign sources. Many of them published for the first time, decades later