In this work interdigitated heterojunction photovoltaic devices were manufactured. A donor layer of P3HT

nanopillars was fabricated by soft nanoimprinting using nanoporous anodic alumina templates. Subsequently,

the PC70BM acceptor layer was deposited by spin coating on top of the P3HT nanopillars using

a solvent that would not dissolve any of the previous material. Anisole solvent was used because it does

not dissolve the bottom donor layer of nanopillars and provides a good wettability between the two

materials. Charge extraction was used to determine the charge carrier densities n on the interdigitated

heterojunction under operating conditions. Moreover, transient photovoltage measurements were used

to find the recombination rate constant in combination with the charge carrier density. At the same time,

the interdigitated structure was also compared with bulk heterojunction and bilayer solar cells manufactured

with the same polymeric and fullerene materials in order to understand the recombination loss

mechanisms in the ordered and disordered nanomorphologies of the active layers.