Photovoltaic Properties in Interpenetrating Heterojunction Organic Solar Cells Utilizing MoO(3) and ZnO Charge Transport Buffer Layers

Organic thin-film solar cells with a conducting polymer (CP)/fullerene (C(60)) interpenetrating heterojunction structure, fabricated by spin-coating a CP onto a C(60) deposit thin film, have been investigated and demonstrated to have high efficiency. The photovoltaic properties of solar cells with a structure of indium-tin-oxide/C(60)/poly(3-hexylthiophene) (PAT6)/Au have been improved by the insertion of molybdenum trioxide (VI) (MoO(3)) and zinc oxide charge transport buffer layers. The enhanced photovoltaic properties have been discussed, taking into consideration the ground-state charge transfer between PAT6 and MoO(3) by measurement of the differential absorption spectra and the suppressed contact resistance at the interface between the organic and buffer layers.