New donor/acceptor polymers PBDTDPT1 and PBDTDPT2 with alternating benzodithiophene and N-alkylated dioxopyrrolo-thiophene were synthesized. The new polymers had deep HOMO levels of -5.42 and -5.44 eV for PBDTDPT1 and PBDTDPT2, respectively. A PBDTDPT2 based BHJ solar cell device achieved a PCE of 4.79% and V(oc) of 0.91 V.

A series of new isoindigo-based low banbap polymers, containing thiophene, thieno [3,2-b]thiophene and benzo[1,2-b:4,5-b 0 ]dithiophene as donors, have been synthesized by Stille cross-coupling reaction. Their photophysical, electrochemical and photovoltaic properties have been investigated. These new polymers exhibit broad and strong absorption between 400 and 800 nm with absorption maxima around 700 nm. The HOMO energy levels of polymers vary between -5.20 and -5.49 eV and the LUMO energy levels range from -3.66 to -3.91 eV. The optical bandgaps of the polymers are optimized for solar cell applications and they are at about 1.5 eV. Polymer solar cells (PSC) based on these new polymers were fabricated with device structures of ITO/ PEDOT:PSS/polymers: PC 71 BM (1:2, w/w)/LiF/Al. The photovoltaic properties of the polymers have been evaluated under AM 1.5G illumination at 100 mW/cm 2 with a solar simulator. The combination of broad absorption, optimal bandgap and well matched energy levels with those of PCBMs makes these isoindigo-based low bandbap polymers promising materials for photovoltaic applications.

Walking is a complex, rhythmic task performed by the locomotor system. However, natural gait rhythms can be influenced by metronomic auditory stimuli, a phenomenon of particular interest in neurological rehabilitation. In this paper, we examined the effects of aural, visual and tactile rhythmic cues on the temporal dynamics associated with human gait. Data were collected from fifteen healthy adults in two sessions. Each session consisted of five 15-minute trials. In the first trial of each session, participants walked at their preferred walking speed. In subsequent trials, participants were asked to walk to a metronomic beat, provided through visually, aurally, tactile or all three cues (simultaneously and in sync), the pace of which was set to the preferred walking speed of the first trial. Using the collected data, we extracted several parameters including: gait speed, mean stride interval, stride interval variability, scaling exponent and maximum Lyapunov exponent. The extracted parameters showed that rhythmic sensory cues affect the temporal dynamics of human gait. The auditory rhythmic cue had the greatest influence on the gait parameters, while the visual cue had no statistically significant effect on the scaling exponent. These results demonstrate that visual rhythmic cues could be considered as an alternative cueing modality in rehabilitation without concern of adversely altering the statistical persistence of walking.