Effect of frontal interface configuration on electronic properties of organic-inorganic hybrid solar cells

Inorganic-organic hybrid solar cells with different frontal interface configurations have been studied. Spin-coated conducting polymer Poly (3,4 ethylenedioxythiophene): poly(4-styrenesulfonate) (PEDOT:PSS) or boron doped a-Si:H films were used as p-type layer. Intrinsic amorphous silicon (a-Si:H) films and P3HT:PCBM heterojunctions were investigated as absorbing layers. Solar cell performance was characterized by current-voltage measurements under AM1.5 illumination and spectral measurements in the range from hν = 1.5 to 3.5 eV. The stack structure with a-Si:H (absorbing layer)/PEDOT:PSS (p-layer) interface exhibited the highest short circuit current density (J_sc). The best open circuit voltage (V_oc) as a large as 0.73 V was observed in the stack structure with a-Si:H/P3HT:PCBM heterojunction as absorbing layer. Finally, in the spectral response of hybrid configurations is possible to distinguish the J_sc contributions of both organic and inorganic layers.