Surface and interface morphology observation and photovoltaic properties of C₆₀/conducting polymer interpenetrating heterojunction devices

Optical and photovoltaic (PV) properties of PV cells with the structure indium tin oxide (ITO)/C₆₀/conducting polymer (CP)/Au have been investigated. The C₆₀/CP heterojunctions in the PV cells were fabricated by spin-coating an organic solution of CP onto the C₆₀ underlying layer. Mixed organic solvents of chloroform and toluene were used to fabricate C₆₀/CP interpenetrating interfaces. The C₆₀/CP interfaces were controlled by adjusting the mixture ratio of chloroform to toluene. From the optical properties and SEM observation of C₆₀/CP heterojunctions, it has been clarified that the interpenetrating interface of C₆₀ and CP contributes to the balance of carrier generation and carrier transport, resulting in superior PV performance.