Julien Klein

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We developed an integrated monochromatic excitation light source integrating sphere based detection system to accurately characterize the absolute photoluminescence quantum efficiency of commonly used polymer light emitting films without using a reference sample. Our methodology is similar to the method reported by de Mello et al. [Adv. Mater. 9, 230(More)
The Atacama Cosmology Telescope is a 6 m telescope designed to map the cosmic microwave background simultaneously at 145, 215, and 280 GHz with arcminute resolution. Each frequency will have a 32 by 32 element focal plane array of transition edge sensor bolometers. The telescope and the cold reimaging optics are optimized for millimeter-wave observations(More)
A new series of organic light emitting copolymers, poly(dioctyl fluorene -co diphenyl oxadiazole)s P(DOFDPO), are reported in this paper. We found organic polymer light emitting devices with comparable device efficiency and more saturated blue color based on this new series of copolymers with less than 10% DPO moiety when compared with poly(dioctyl(More)
Thin large-grained polycrystalline silicon (poly-Si) films can be formed on glass by aluminium-induced crystallisation (AIC) of amorphous silicon (a-Si) in an annealing process below the eutectic temperature of the Al/Si system. The influence of increasing the temperature during the anneal as well as the modification of the initial aluminium layer was(More)
Large-grained polycrystalline silicon (poly-Si) films were prepared on foreign substrates by epitaxial thickening of seed layers. The seed layers were formed by the aluminum-induced layer exchange (ALILE) process which is based on aluminum-induced crystallization (AIC) of amorphous silicon (a-Si). The epitaxial thickening was carried out at two different(More)
Ti:Sapphire (Ti:Sa) was initially proposed and demonstrated as a near-infrared gain medium in 1982, and was commercialized by Spectra-Physics in 1988 with the launch of a continuous-wave laser. Th is was followed in 1990 by a picosecond mode-locked oscillator, and in 1991 with a femtosecond version. Soon aft er this, the whole ultrafast research community,(More)
2014 Tunneling spectroscopy at high bias has proved to be useful as a tool for studying electronic excitations in junctions although one major difficulty encountered is the huge background in the second derivative of the tunneling characteristics I(V). This background however depends on which second derivative is used. We compare the sensitivity of the(More)
We reported on one new series of light-emitting copolymers for polymer light-emitting devices (PLEDs), poly(dioctyl fluorene-codiphenyl oxadiazole)s (P(DOF-DPO)s). The device structure used in this study was composed of: indium tin oxide (ITO) anode/PEDOT:PSS ((polyethvlenedioxythiophene)–poly(styrene sulfonate)) as hole-transporting layer/P(DOF) or(More)
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