Molecular organic crystalline matrix for hybrid organic–inorganic (nano) composite materials

Investigation of emission properties of doped aromatic derivative organic semiconductor crystals

“…From geometrical considerations, iodine and silver atoms penetrate the lattice during the growth and, most probably, can be localized in interstitial void sites. Sodium atoms could be incorporated in benzil in the interstitial positions with difficulty, only by a local deformation of the lattice, because the atomic diameter is greater than the diameter of free space in benzil unit cell, evaluated at 2.9 Å [8,9]. These dopants rise the melting point of the m-DNB and benzil matrix and their segregation coefficients are k41.…”

“…Photoluminescence has been measured at room temperature on bulk pure and doped, mechanically polished wafers of crystalline m-DNB and benzil obtained from ingots grown from melt in a vertical configuration, by the Bridgman-Stockbarger method modified for organic material crystallization [6][7][8][9]. The thermal growth conditions, characterized by a steep gradient at the crystal/melt interface, are a compromise between those necessary to compensate the high constitutional supercooling and the facetted growth morphology, phenomena sustained by the low melting temperature (90 1C for m-DNB and 95 1C for benzil) and high enthalpy of fusion (17.36 kJ/mol for m-DNB and 23.56 kJ/mol for benzil).…”

“…This is a spin forbidden transition for separate molecules, which becomes possible because of the vibrational interactions in our crystalline lattice [6,12,17]. Charge transfer is possible between Ag and benzil because its first ionization energy is large (D 1 H Ag =731 kJ/mol), and between Na and benzil because two donor atoms of Na could give each of the outer 3s electrons to two oxygen atoms of the two acceptor carbonyl groups in benzil characterized by a strong electron affinity [8]. Theoretically, silver shows in benzil the same tendency for clustering anticipated for iodine in m-DNB, but no evidence of this process has been observed.…”

“…The interest for studying organic crystals can also be justified by the perspective to use these materials as crystalline host matrices for inorganic [4][5][6][7][8][9] or organic guests [6,[9][10][11]]. An organic matrix can assure an efficient fluorescence mechanism, while the guest component can improve some properties such as electrical mobility, thermal stability, magnetic and dielectric transitions and can also influence the emission properties of the matrix.…”

Organic Semiconductor Based Heterostructures for Optoelectronic Devices

“…This method has been also used for the preparation of doped organic semiconductor layer. As dopants have been used oxine (8-hydroxyquinoline) or resorcinol (1, 3 dihydroxybenzene) in m-DNB and Na or Ag or m-DNB in benzil (Stanculescu, 2005;Stanculescu, 2006 b). Thin films of organic molecular compounds with T melting >100 °C have been prepared by vacuum evaporation and deposition processes that allows the preparation of stable, homogeneous films with a specified geometry and a good adhesion to the substrate Stanculescu, 2008;Rasoga, 2009).…”