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Wavelength (nm) Voltage (V)

Fig. 8.27 Photovoltaic properties of ITO/PEDOT-PSS/in situ-TiOx:MDMO-PPV/LiF/Al devices 4:1 (v/v) (a) External quantum efficiency. (b) J-V curve in the dark (dashed line) and under illumination (~70 mW/cm2) (solid line). Reprinted with permission from Adv. Mater. 2003, 15, 118 [211]. Copyright 2003 Wiley-VCH

Wavelength (nm) Voltage (V)

Fig. 8.27 Photovoltaic properties of ITO/PEDOT-PSS/in situ-TiOx:MDMO-PPV/LiF/Al devices 4:1 (v/v) (a) External quantum efficiency. (b) J-V curve in the dark (dashed line) and under illumination (~70 mW/cm2) (solid line). Reprinted with permission from Adv. Mater. 2003, 15, 118 [211]. Copyright 2003 Wiley-VCH

conversion efficiency of h = 0.2%. Integration of the measured spectral response of the cell with the AM1.5 solar spectrum affords an estimate for the short circuit current density under AM1.5 conditions (1,000 W/m2) of Jsc = 0.87 mA/cm2 [211]. In a subsequent study, Slooff et al. confirmed these results for in situ-TiOx:MDMO-PPV (J = 0.6 mA/cm., V = 0.60 V, and FF = 0.43, h = 0.22% at 70XmW/cm2) and v sc oc ' '

showed that the procedure is also applicable to polythiophene derivatives [212]. For an in situ-TiO :P3OT active layer they found J = 0.7 mA/cm2, V = 0.45 V, and FF

x sc oc

Wang et al. followed a similar approach using a triethoxysilane-containing poly(3-nonylthiophene) (P3NT) and Ti(i-PrO)4 to make hybrid in situ-TiOx/P3NT material [213] . The presence of the silane group effectively prevented the macroscopic aggregation of TiO. during the sol-gel reaction, leading to more uniform distribution of TiO2 throughout the sample and a better PL quenching. This promising material, however, has not been tested in solar cells so far.

While the in situ TiOx synthesis has various potential advantages in terms of creating an intimate mixing, the main drawback of the use of in situ prepared TiOx is that the resulting inorganic phase is essentially amorphous. Crystallization of TiO2 would require high temperatures (>350°C [214]). Hence, it is likely that the presence of an amorphous TiOx phase, rather than a crystalline network of TiO2 , limits the charge transport in photovoltaic devices based on this method.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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