FTIR spectroscopic analysis and STM studies of electroluminescent Eu(DBM)3 bath thin films vacuum deposited onto Au surface

Light-Emitting Diode of Planar Type Based on Nanocomposites Consisting of Island Au Film and Organic Luminofore Tb(thd)3

“…The local I-V curves measured for nano-sized areas of monolayer Tb(thd) 3 films are also linear at the voltages 0 < U < 0.4 V showing a super linear character at voltages above 1 V. The light emission from such films induced by STM tunnel current was observed under the applied voltage of 1.5 V, that corresponds to the local electric field strength of $3Á10 8 V=m. This value fairly agrees with the electric field strength value, at which the electroluminescence is usually observed in the metal-organic nanocomposites [7].…”

“…4a), they are strongly asymmetric with respect to applied voltage being linear at the voltages À0.8<U<0.5 V and showing the oscillations at higher voltages. The similar behavior, though much more pronounced, was observed for VD layers of Eu(dbm) 3 bath in our earlier paper [7] and was attributed to loose packing of bulky organic ligands around europium ions and their perturbations induced by the electric field of the STM tip. Smaller oscillating behavior of locally recorded asymmetric I-V curves of the VD Tb(thd) 3 films indicates that (thd) ligands are more closely packed around terbium ions than the bulkier (dbm) 3 bath ligands.…”

“…As it was shown in our previous papers [5,7], the light emission observed under the electric current passage through a nanocomposite structure consisting of island metal films and molecules of rare earth complexes shows the features peculiar to the corresponding organic compounds and to the metal nano-islands. Therefore, the fabricated planar nanodevice can be used as a light source with controllable emission spectrum both of extended and submicron dimensions.…”

“…For the recording of local I-V curve, the scan was stopped and the feedback loop was switched off in order to apply a voltage ramp within the limits from À1.2 V to þ1.2 V. At higher voltages the measurements of I-V curves have not been performed because of influence of electric field on film morphology. The fabrication procedure of planar nanocomposite device was described in detail elsewhere [6,7]. The organic molecules were deposited onto Au nano-islands grown in a $30 m gap between two gold electrodes.…”

“…The efficiency of an OLED strongly depends on the choice of molecules and on the design of device structure. In order to obtain more effective and useful OLEDs using lanthanide-based compounds, we proposed in our recent works [5][6][7] a new type of planar nanoscale EL device consisting of an island metal film and organic molecules. It is known [8] that when electric current passes through metal nano-islands, they emit electrons and photons capable to provide effective energy transfer to the organic layer.…”