抄録
The ultra-flexible organic photovoltaics (OPV) have light weight and great mechanical characteristic that they can deform like bending, compressing and extension. The ultra-flexible OPV with these unique characteristics is expecting as next generation energy harvesters in soft robotics field and wearable electronics field because such research fields are needed the flexible electronics included flexible energy harvester to increase the performance of themselves. All of photovoltaics have angle dependence which is that amount of generated electricity is changed depend on angle of incident lights. Especially, in case of ultra-flexible OPV for applying the soft robotics field and wearable electronics field, suppression of angular dependence is needed because such devices are constantly deforming and the angle of incidence to the ultra-flexible OPV is constantly changing. Some previous works have shown suppressed angular dependence by nano-patterning relatively thick (order of 100 µm) polymer film substrates. However, it is difficult to do nano-patterning onto 1 µm thick substrates because extremely susceptible to damage like heat, compression, solvent and ultraviolet light by conventional patterning methods like laser curving and soft lithography. Here, we show the newly low energy patterning method with dimethylpolysiloxane and fluorinated layer for 1 µm thick thin film substrates. By using our method, 1 µm thick thin film substrates with nano-pattern pitch of 760nm and maximum height of 110 nm
were fabricated. Furthermore, ultra-flexible OPV using nano-patterned thin film substrate was exhibited lower angular dependence than ultra-flexible OPV with non-patterned thin film substrate, especially, it was exhibited lower 5.7% of angular dependence than normal one at 50 degrees of incident angle.
