The principle remaining challenge in the research area of organic photovoltaic (OPV) materials is to develop solar cells that combine high efficiency, stability and reproducibility.

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We report the fabrication and characterisation of an organic-inorganic hybrid Photodiode (HPD) based on PCPDTBT and Zinc Oxide (ZnO) photoactive layers. The main benefit of using these materials is that multi spectral light sensing from the UV through to the Near Infrared is achieved, encompassing wavelengths ~350nm-870nm. To our knowledge, this is one of the widest range responses reported for an inorganic-organic hybrid photodiode. The evaluation of the technology shows the devices exhibit one of the lowest levels of dark currents reported for a HPD, but some limitations exist due to a low on-off ratio and non-linearity of the responsivity at low incident power.The stability of devices made with PCPDTBT:ZnO active layers is compared to more commonly reported P3HT:ZnO devices in dark and it is shown that using PCPDTBT substantially improves lifetime. Highlights-Wide photoresponse from UV to the NIR is achieved -Device exhibits low dark current and high rectification ratio for a hybrid device -Responsivity is measured and shown to be linear for incident power> 0.04W/cm 2 -Improved lifetime observed with PCPDTBT active layer, when compared to P3HT-based devices

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By employing phase transfer catalysis, formaldehyde acetals were synthesized from the reaction of alcohols and dibromomethane at moderate temperatures. Using a high alkaline concentration, the reaction could be improved to obtain a 100% yield by reacting dibromomethane and 1-alcohol employing tetrabutylammonium bromide (TBAB) as a phase transfer catalyst. Six kinds of alcohols with various structures, four sorts of solvents with various dielectric constants and seven types of catalysts were examined to test their reactivities to the reactions. Only one unique product with two alkoxides substituents was observed which indicated the presence of a rather fast reaction rate during the second reaction of the organic phase. The reaction was dramatically enhanced by adding a small amount of quaternary ammonium salt (QX) to obtain a 100% yield utilizing the alcohols with nonbonding electron pairs within a short period of reaction time. The conversion was also observed to be strongly dependent upon the structure of the quaternary ammonium salts. The reaction rate and the product yield were satisfactorily accounted for the chemical reaction equilibrium of alcohols and KOH in the aqueous phase, the hydration of the active catalyst (QOR) in the organic phase and the distribution of QOR between two phases.