초록 |
An interest of one of significant technical challenges in organic solar cell is to fabricate large-area flexible bulk heterojunction(BHJ) solar cells. In order to accomplish this task, there are some requirements to be achieved; (i) large tolerance of the maximum photoconversion efficiency (PCE) to the film thickness, (ii) fast hole transport in both the thickness and lateral directions of the BHJ layer, and (iii) enhanced stability against bending and heat. We demonstrates that nearly 100% crystalline long P3HT nanofibrils which applied cool-and-heat(C&H) process with a P3HT/PCBM in m-xylene solution. We found that the hole transport of the nanofibril composite was 2.6 times faster in the thickness direction and 6.5 times more conductive in the inplane direction compared with conventionally annealed composites. The faster hole transport in the thickness direction led to negligible dependence of the PCE on the thickness of the composite layer. |