NiO is a p-type wide bandgap semiconductor of use in various electronic devices ranging from solar cells to transparent transistors. This work reports the controlling of conductivity and increase of work functions by Li doping.

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Soluble conjugated alternating porphyrin-dithienothiophene copolymersssingle-bond linked (I) and triple-bond linked (IIa and IIb)swere synthesized by palladium(0)-catalyzed Stille and Sonagashira coupling reactions, respectively. The thermal, electrochemical, optical, charge transport, and photovoltaic properties of these copolymers were examined; the effect of the triple bond was studied. I exhibits onset decomposition temperature (T d ) of 410°C and glass-transition temperature (T g ) of 180°C, higher than those of IIb (T d , 330°C; T g , 130°C). The absorption spectrum of I in thin film exhibits a sharp Soret band at 450 nm and two weak Q-bands at 563-619 nm, while IIb exhibits a sharp Soret band at 491 nm and a strong Q-band at 760 nm. The emission maxima of I and IIb in solution are located at 642 and 722 nm respectively. IIb is electrochemically active in both the oxidation and reduction regions, while I shows only oxidation peak. The field-effect hole mobilities as high as 2.1 × 10 -4 cm 2 V -1 s -1 were obtained for these copolymers. Polymer solar cells (PSCs) were fabricated based on the blend of the polymers and methanofullerene [6,6]-phenyl C61-butyric acid methyl ester (PCBM). The power conversion efficiency (PCE) of 0.3% was achieved under AM 1.5, 100 mW/cm 2 for the PSC using IIb:PCBM (1:3, w/w) as active layer. The PCE of the PSC based on IIb:PCBM (1:3, w/w) is double that based on I:PCBM (1:2, w/w), consistent with that IIb exhibits stronger Q-band absorption and higher mobility at room temperature.