Mitigating the Undesirable Chemical Reaction between Organic Molecules for Highly Efficient Flexible Organic Photovoltaics.

Organic photovoltaics (OPVs) with nonfullerene acceptors (NFAs) feature excellent device performance and device stability. However, they are facing problems when the amine-rich polyelectrolytes are used as cathode interfacial layers. In this work, a small molecule, ethanedithiol (EDT) at the polyethyleneimine ethoxylated (PEIE)/active layer interface is inserted for mitigating the undesirable reaction between amine-rich groups and electron-acceptor moieties in NFA.

Treating the Poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonate) Surface with Hydroquinone Enhances the Performance of Polymer Solar Cells.

The introduction of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as a standard hole transport layer greatly increased the efficiency of early organic solar cells. However, because PEDOT:PSS has a metallic property, it can still form a barrier by means of metal-semiconductor contact at its interface with the photoactive layer. In this study, we modified the PEDOT:PSS surface with hydroquinone (HQ) to remove that barrier.

Spontaneous and applied potential driven indium recovery on carbon electrode and crystallization using a bioelectrochemical system.

Indium removal and recovery on a carbon electrode under a microbial fuel cell (MFC)-based oxidation/reduction reaction were examined using synthetic wastewater. More than 90% of In ions were removed after continuous operation of the MFC for 14 days with an average current generation of ∼50 μA. During operation, indium particulates formed on the cathode carbon electrode.

Characterization of opto-electrical enhancement of tandem photoelectrochemical cells by using photoconductive-AFM.

Solar-to-hydrogen conversion by water splitting in photoelectrochemical cells (PECs) is a promising approach to alleviate problems associated with intermittency in solar energy supply and demand. Several interfacial resistances in photoelectrodes limit the performance of such cells, while the properties of interfaces are not easy to analyze in situ. We applied photoconductive-AFM to analyze the performance of WO/pn Si photoanodes, containing an ultra-thin metal interface of either Au or Pt.

Polymer Film-Based Screening and Isolation of Polylactic Acid (PLA)-Degrading Microorganisms.

Polylactic acid (PLA) has been highlighted as an alternative renewable polymer for the replacement of petroleum-based plastic materials, and is considered to be biodegradable. On the other hand, the biodegradation of PLA by terminal degraders, such as microorganisms, requires a lengthy period in the natural environment, and its mechanism is not completely understood. PLA biodegradation studies have been conducted using mainly undefined mixed cultures, but only a few bacterial strains have been isolated and examined.

Amine-Based Interfacial Molecules for Inverted Polymer-Based Optoelectronic Devices.

The change in the work function (WF) of ZnO with amine-based interfacial mole-cules (AIM) can be controlled by the number of amine groups. AIM with a larger amine group can induce a stronger interface dipole between the amine groups and the ZnO surface, leading to a greater reduction of the WF.

Selective modulation of charge-carrier transport of a photoanode in a photoelectrochemical cell by a graphitized fullerene interfacial layer.

We show that a graphitic carbon interfacial layer, derived from C70 by annealing at 500 °C, results in a significant increase in the attainable photocurrent of a photoelectrochemical cell that contains a WO3 -functionalized fluorine-doped tin oxide (FTO) photoanode. Time-resolved photoluminescence spectroscopy, photoconductive atomic force microscopy, Hall measurements, and electrochemical impedance spectroscopy show that the increase in photocurrent is the result of fast and selective electron transport from optically excited WO3 through the graphitic carbon interfacial layer to the FTO-coated glass electrode. Thus the energy efficiency of perspective solar-to-fuel devices can be improved by modification of the interface of semiconductors and conducting substrate electrodes by using graphitized fullerene derivatives.

Study on Ag mesh/conductive oxide hybrid transparent electrode for film heaters.

Ag mesh-indium tin oxide (ITO) hybrid transparent conductive films were fabricated and evaluated for use in film heaters. PS monolayer templates were prepared using highly mono-dispersed PS spheres (11.2 μm) obtained by a filtering process with micro-sieves.

Cr-Si Schottky nano-diodes utilizing anodic aluminum oxide templates.

We have fabricated Cr nanodot Schottky diodes utilizing AAO templates formed on n-Si substrates. The diameters of the diodes were 75.0, 57.

Role of additional PCBM layer between ZnO and photoactive layers in inverted bulk-heterojunction solar cells.

In order to induce greater light absorption, nano-patterning is often applied to the metal-oxide buffer layer in inverted bulk-heterojunction(BHJ) solar cells. However, current homogeneity was significantly disturbed at the interface, leading to an efficiency that was not fully optimized. In this work, an additional PC61BM layer was inserted between the ZnO ripple and the photoactive layer to enhance the electron extraction.

Design of magnetic resonance force microscopy probe based on a commercially available charge coupled device camera.

The technique of magnetic resonance force microscopy (MRFM) is proposed with the purpose to enhance the sensitivity of the inductively detected conventional magnetic resonance technique. The IBM MRFM group demonstrated magnetic resonance imaging (MRI) to the nanoscale level by using MRFM. The spatial resolution of the inductive method is on the order of a few micrometers.

Characterization of the oxygen oonosorption effect on a single SnO2 nanowire by using conductive atomic force microscopy.

We have verified that SnO2 nano-wire has an n-type semiconductor property and it can be a p-type one when it is exposed to O2. We employed conductive AFM system to measure the I-V curve and resistance of single SnO2 nano-wire which had been synthesized on the Au thin film by a thermal process. To analyze a effect of O2 ionosorption into nano-wire, resistance was measured with various O2 concentration and we observed increment and maintenance of resistance which caused by O2 ionosorption.

Synthesis and characteristics of NH2-functionalized polymer films to align and immobilize DNA molecules.

We developed a method to use NH2-functionalized polymer films to align and immobilize DNA molecules on a Si substrate. The plasma-polymerized cyclohexane film was deposited on the Si substrate according to the radio frequency plasma-enhanced chemical vapor deposition method using a single molecular precursor, and it was then treated by the dielectric barrier discharge method in a nitrogen environment under atmospheric pressure. Changes in the chemistry of the surface functional groups were studied using X-ray photoelectron spectroscopy and Fourier transformed infrared spectroscopy.