Alexander A. Maleev

Electroluminescent properties of lanthanide pentafluorophenolates

Lanthanide pentafluorophenolates Ln(OC6F5)3(L)x (Ln = Pr, Nd, Sm, Eu, Dy, Ho, Er, Yb; L = 1,10-phenanthroline, 2,2′-bipyridine; x = 1 and 2) are used as emissive layers in organic light emitting devices (OLEDs). Single-layer ITO/Ln(OC6F5)3(L)x/Yb devices reveal no electroluminescence (EL) with the exception of Tb-derivative-based OLEDs. Bilayer ITO/TPD/Ln(OC6F5)3(L)x/Yb samples exhibit a broad band emission peaked at 580 nm assigned to an electroplex at the TPD/complex interface. Besides, the spectra of the devices based on Pr, Nd, Sm, Eu, Er, Tb and Yb derivatives contain the characteristic narrow bands of f–f transitions. Terbium-based bilayer OLEDs exhibit unusual changes in the EL spectra with increasing the applied voltage. The emission color of the devices tunes from orange towards green. The possible nature of the phenomenon is discussed.

A Hybrid CuI/Fullerene Heterojunction in Transparent Flexible Photovoltaic Cells

We report on the fabrication and testing of multilayer thin-film photovoltaic cells based on a hybrid cuprous iodide/fullerene (CuI/C60) heterojunction. The cells were prepared by thermal evaporation of components on flexible polyethylene terephthalate (PET) substrates. The 0.4-V open circuit voltage (Uoc) arising at the junction does not depend on the thickness of the fullerene layer and on the introduction of a blocking layer at cathode. However, these changes strongly affect the short circuit current. A distinctive feature of such cells is high transparency in the entire visible range, which makes them potentially interesting for application in tandem (or multijunction) photovoltaic structures in order to enhance Uoc.

Reactivity of neodymium and samarium nitrides

The reaction of NdN and SmN with iodine gave the iodide-nitrides (NdI2)3N(DME)4 and (SmI)3N2(THF)2, which are inert towards sulfur, in contrast to the neodymium and dysprosium iodide-nitrides prepared by the reaction of LnI2 with N2. Reaction of NdN and SmN with C6F5OH and CpH gave the organolanthanide derivatives Ln(C5F5O)3(THF)n (Ln = Nd or Sm) and Cp3Sm with moderate and low yields, respectively. Phenylacetylene and styrene do not react with SmN.

Lanthanide complexes with the Schiff base containing sterically hindered phenol: Synthesis, structure, and luminescence properties

The syntheses of the 2,6-di-tert-butyl-4-(2-hydroxybenzylideneamino)phenolate (L) complexes of Gd (I), Nd (II), Er (III), Yb (IV), Tm (V), Sm (VI), and Tb (VII) are described. The structures of the Gd and Er complexes are determined by X-ray diffraction analysis (CIF files CCDC nos. 1558820 (I) and 1558819 (III)). All synthesized compounds exhibit ligand-centered photoluminescence in a range of 405–485 nm. In addition, the luminescence spectra of solid samples of the neodymium and ytterbium complexes contain narrow bands of f–f transitions characteristic of Nd3+ and Yb3+ ions.

Study of thermochemical properties of lanthanides pentafluorophenolates with coordination ligands

Saturated vapor pressure of lithium pentafluorophenolate and the lanthanide complexes as a function of temperature has been determined by the Knudsen effusion method. Processing of the pressure data allowed the calculation of thermodynamic parameters of the compounds sublimation. Mass spectra and differential scanning calorimetry data are presented.

Photovoltaic properties of Zn, Al, La, Sm, and Yb complexes with o-iminobenzoquinone ligands

The o-iminobenzoquinone complexes of lanthanum, samarium, and ytterbium, Ln(L)3 (L = 3,5-ditert- butyl-1,2-quinone-1-(2-oxy-3,5-di-tert-butylphenyl)imine) are synthesized. In order to study the photovoltaic properties of the obtained complexes and previously synthesized similar complexes of zinc and aluminum M(L)2 prototypes of photovoltaic cells are prepared on their basis. An examination of the fabricated devices has revealed that nanolayers of all the compounds, except for ytterbium complex, exhibited photovoltaic properties. The best results of energy conversion are achieved for single-layer cells containing zinc complex as a photoactive material (Open-circuit voltage UOC = 1.01 V, short-circuit current JSC = 5.2 nA/cm2).

Monophthalocyanine complexes of samarium and terbium with axial ligands: synthesis, structure and optoelectronic properties

Abstract The monophthalocyanine complexes of samarium and terbium containing axial 2-mercaptobenzothiazole (PcSm(MBT) (1)), 2-(2-benzoxazol-2-yl) phenolate (PcTb(OON) (2)) or 2-(2-benzothiazol-2-yl)phenolate (PcTb(SON) (3)) ligands were synthesized and identified by elemental, LDI-TOF and X-ray (for 1) analysis. Photoluminescence (PL) and electroluminescence (EL) spectra of the compounds contained only emission bands of phthalocyanine and axial ligands but did not contain the bands of f-f transitions. It was found that among the complexes 1, 2, 3 the latter had highest photoconductivity (~10−7 S/cm) and photovoltaic properties. An organic photovoltaic device (OPV) of configuration of ITO/3/C60/Alq3/Al revealed open-circuit voltage (VOC) of 0.24 V and short current density (ISC) of 0.3 μA/cm2 under illumination by a xenon lamp at 17 mW/cm2.