| 초록 |
The charge collection efficiency of CuPc/C60 based planar heterojunction solar cell is investigated. Photocurrents are generated not only from the excitation of donor, CuPc but also acceptor, C60. From the IPCE spectrum, we have observed that the photocurrents generated from the excitation of C60 layer are sensitively varied with applied dc bias. That means the dc bias dependent changes of photocurrent during the illumination are mainly affected by the charge generation in the C60 layer. To find out the origin, The dc bias response of 1st electroabsorption and photocurrent generation from the C60 single layer device were examined by the excitation of CuPc and C60 layer independently using HeCd laser (442 nm) and HeNe laser (633 nm). Results reveal that the photocurrents are generated not only the CuPc/C60 interface but also bulk of C60. Also, charges generated inside the C60 bulk can shift the built-in potential of the C60 layer. |
