Metal-organic (MO)CVD processes using three different precursors (Bi(tmhd) 3 , 3 , and Bi(o-tol) 3 ) have been investigated. Combined, thermal, and mass spectroscopic investigations have provided information on their thermal robustness during sublimation processes. In-situ Fourier-transform infrared (FTIR) measurements have allowed the monitoring of masstransported precursors during MOCVD experiments. Temperature windows of 190±277 C, 170±270 C, and 150±220 C have proved suitable for the efficient vaporization of Bi(tmhd) 3 , Bi(p-tol) 3 , and Bi(o-tol) 3 , respectively, even though aryl precursors have proved to be more stable than b-diketonate during the sublimation and transport processes.Above 350 C, decomposition during the MOCVD processes has been observed for all the precursors. In the case of Bi(tmhd) 3 and Bi(o-tol) 3 it involves the ligand fragmentation, while for Bi(p-tol) 3 , dissociation of the intact aryl ring seems to occur.

Experimental methods for the characterization of dryers for OLED/PLED applications were addressed and results are reported and compared. Different commercially available dryers were tested. It turned out that test conditions can significantly affect the results of the characterization. For example, dryers showing a low total theoretical capacity can, on the contrary, show very good performances if tested using methods and conditions closer to the operating conditions expected to occur inside OLED/PLED devices. The measured sorption performances were used to calculate how water concentration inside a display evolves during lifetime of the device itself. These calculations show the effect and the benefit that can be obtained by the use of a specific dryer. Different measurement methods were compared and considerations for the selection of a suitable charachterization test are given.

Metal-organic (MO)CVD processes using two different precursors, (La(tmhd) 3 and La(tmod) 3 ), have been investigated. Insitu Fourier transform infrared (FTIR) spectroscopy investigations and thermal analysis have provided information on their thermal robustness during the sublimation processes and mass-transport properties during MOCVD experiments. Both precursors can be efficiently vaporized in the temperature range 160-230°C even though La(tmod) 3 exhibits higher volatility. Lanthanum oxides have been efficiently deposited using a direct liquid injection (DLI) equipped MOCVD reactor in the temperature range 350-500°C for both precursors. The effect of the addition of tetraglyme to the precursor solution has been evaluated. Films mainly consist of different phases of La 2 O 3 and LaO(OH), while the carbon-containing La 2 O 2 CO 3 phase was observed only on the surface, with no relevant carbon contamination being present in the bulk of the film.

Objective and backgroundOne of the key issues for organic light emitting diodes (OLEDs) is to achieve high electro-luminescence external quantum efficiency (η ext ), high power efficiency (η E ) [1] and long-term stability. These goals imply extremely efficient electron injection and thus low driving voltage, together with high electron mobility in the organic layer and therefore high recombination efficiencies. The cathode structure and the metal-organic (M-O) interface are the major responsible for the desired performance improvements. Since 1987 Tang and Van Slyke [2] adopted a cathode structure based on composite MgAg alloy able to reduce the overall cathode work function and the barrier height for the electron injection. Recently, these OLED issues have been examined in the context of optimizing electron injection through the incorporation of an alkali metal inside the cathode structure. The first appearance of alkali metals to obtain a low driving voltage OLED was in 1983, when Partridge used Na, K and Cs as efficient electron injection cathodes in a PVK based OLED [3] . In the present work and in broad literature works, deep studies have been carried out on the usage of Li and Cs. Alkali metals incorporation in the OLED structure can be accomplished in two forms:o ultra-thin layers (Li, LiAl, Li 2 O, LiF, Cs, CsAl, CsF and alkali-metal carboxilates) above the electron transport layer (ETL) and capped by an Al back electrode [4][5][6][7][8] o co-deposition of Li or Cs with an ETL immediately prior to the cathode deposition [9][10][11][12][13][14][15][16][17] (also named "alkali metal doping of ETL") Both configurations have been shown to dramatically reduce the drive voltages and, in the meantime, increase the external quantum efficiency, the overall luminance and the long-term operational stability. Moreover, the creation of an electron injection layer (EIL) both by the interlayer between ETL and cathode and by ETL doping, employing transparent cathodes, such as ITO, has been shown excellent improvements in both η ext and η E also for Top-Emission device architectures (TOLEDs) [18] and for Stacked structures (SOLEDs). Transparent cathodes built up using CuPc or BCP capped with RF sputtered ITO, are conformal with the adoption of an alkali metal like Li. Such cathodes structures are useful for OLEDs integrated with silicon TFT driver electronics for Active-Matrix displays (AMOLEDs), micro-emissive displays, head-up displays, white displays as backlighting. Finally, alkali metals have been successfully used also in PLED structures, mainly in conjunction with standard polymers like MEH-PPV, and with metallic cathodes like Al and Au [19][20][21] . As a side effect of the adoption of alkali metals inside the OLED structure, the organic materials experienced longer lifetime and stability due to the reduced electrical stresses. The device exploiting alkali metals can reach the same performances of a standard device using lower driving voltages and thus lower electric fields [13,22] (see fig.1 below). Starting fro...

We are reporting on the modification of Pb(Zr,Ti)O 3 (PZT) thin films by substitution of Ba for Pb. The (Pb,Ba)(Ti,Zr)O 3 (PBZT) films are grown on iridium coated silicon substrates by a liquid delivery MOCVD technique. Four separate solutions of Pb (DPM) 2 , Ba (DPM) 2 , Ti (O i Pr) 2 (DPM) 2 , and a new zirconium precursor Zr (IBPM) 4 were used. A PZT(30/70) film of 150 nm thickness shows a P r value of 35 µC/cm 2 , and E c of 90.4 kV/cm. Ba substitution leads to suppressed tendency for phase separation, more homogeneous surface morphology, smaller grain sizes and easier growth with respect to adjustment of stoichiometry. PBZT films show low dielectric losses of 0.03 and high permittivity values of up to 1000. A decrease of the coercive field could not be observed.