Effects of metallophthalocyanines (MPcs) are systematically investigated on electroluminescence (EL) characteristics of ITOy MPcyTPDyAlq3yMg-Ag devices. A linear relationship is found between driving voltages of the devices and energies of the highest occupied molecular orbital (HOMO) level of MPcs, showing that the driving voltage of the device is substantially determined by the energy barrier for hole injection at the ITOyMPc interface. When an MPc having a higher HOMO level, such as CuPc or ZnPc, is selected as a hole transport material, the driving voltage of the device at a luminance of 100 cd my2 significantly reaches as low as 5.5 V compared with 7.8 V for the device without an MPc layer. The insertion of MPc layer leads to increasing of the EL output, but does not affect the EL efficiency of the devices.

Electroluminescence (EL) characteristics of the double-MPc-layered devices consisting of ITO/MPc1/MPc2/Alq3/Mg-Ag were investigated, where MPc1 and MPc2 represent two metallophthalocyanines and Alq3 stands for tris(8-quinolinolato)aluminum(III). A compatible double-MPc-layered structure led to a decreased hole-injection barrier at the ITO/MPc1 interface and an increased electronblocking ability of the MPc2 layer in the device. The EL efficiency of the device was improved further by using a 4,40-bis(m-tolyphenylamino) biphenyl (TPD) layer as an additional hole-transport layer due to its good electron-blocking ability. For the double-MPc-layered devices with a TPD layer, the EL performances were dependent primarily on the electronic structure of ITO/MPc1 interface rather than that of MPc1/ MPc2 or MPc2/TPD interface.

Self-assembled monolayers (SAMs) of two tripod-shaped p-conjugated thiols and a disulfide have been grafted onto Au(111)/mica substrates. These SAMs exhibit oxidation and reduction peaks in the cyclic voltammograms arising from the electrochemical responses of the conjugated oligothiophene parts in the molecules. Organic light-emitting devices have been fabricated by using the SAM-coated Au electrode as the anode. In comparison with the device consisting of Au/TPD/Alq3/Mg-Ag, the electroluminescence performance of the device using the SAM grafted Au electrode is much improved for the SAM of the tripod-shaped thiols and worsened for the SAM of the disulfide. The different influences of the SAMs on the performances are explained by considering structures of the molecules and the SAMs, and the energy level alignment at the related interfaces in the devices.

Influences of an inserted hole-blocking bathocuproine (BC) layer were investigated on electroluminescence (EL) performances of organic light emitting devices with a configuration of ITO/BC/Alq3/Mg–Ag, where Alq3 is tris(8-quinolinolato)aluminum(III). Variations in the thickness of organic layers and bias voltages were found to alternate the emissive region from the BC layer to the Alq3 layer, resulting in shift of the emission wavelength in the EL spectra of the devices.

A strain of Thiobacillus Denitrificans (TD) isolated from the soil was selected to reduce the corrosion caused by Sulfate Reducing Bacteria (SRB). The optimal pH was determined as 7.0 for the growth of TD. The growth environment of TD was found to be similar to that of SRB. Thus they can be cultured together. When they were grown together, it was observed that TD reduced the corrosion caused by SRB, being attributed to that TD might consume corrosive sulfides produced by SRB and restrict the SRB biofilms from accumulation. Scanning probe microscopy observations ex-situ demonstrated that the topography of mixture biofilm formed in the mixed culture of TD and SRB was more compact than that for SRB along. Therefore, the process of charge transfer is baffled, leading to a decrease of the corrosion caused by SRB.