| 초록 |
Recently, Power Conversion Efficiency(PCE) of polymer photovoltaic has been facing limitation due to low conductivity of organic materials. Many research groups have used Carbon Nano Tube(CNT) because of its high conductivity. We demonstrated the improvement of photovoltaic PCE based on poly(3-hexylthiophene-2,5-diyl)(P3HT) and [6,6]-phenyl-C61 butyric-acid methyl-ester(PCBM) bulk heterojunctions by using p-type Single-wall Carbon Nano Tube(SWCNT) under P3HT:PCBM layer. SWCNT formed by various methods(i.e. mixed 0.01 wt% with PEDOT:PSS, with IPA, with PEDOT:PSS added with de-ionized water and surfactant Sodium dodecyl sulfate (SDS), and without SWCNT) were mixed in sonication during 24 hours then SWCNT layer was fabricated on patterned ITO by spray 10 times under 1.5 mmHg pressure for 0.2 sec at once and annealed at 140 ℃ for 10 min on hot plate. The distance between spray nozzle and substrate was 30 cm. The PCE of without SWCNT under P3HT:PCBM was shown 3.713% and that of PEDOT:PSS with SWCNT layer device was 3.696%. Furthermore, The PCE of PEDOT:PSS with SDS layer device was 4.328%. The maximum PCE was observed 4.913% in IPA:SWCNT layer device. In particular, the performance of this device was obtained 14.48mA/cm2 of short-circuit current (Jsc), 0.595 V of open circuit voltage (Voc), and 57% of fill factor (FF). Other devices mixed with SWCNT showed lower PCE than that of only mixed IPA because other devices had poor morphology due to be formed by spray method. Device that used IPA:SWCNT layer between the patterned ITO and active layer showed high current density and PCE, which was confirmed the property of CNT, i.e. high conductive material. In conclusion, The characteristics of IPA:SWCNT polymer solar cell was improved by 18.92% of Jsc , 8.24% of FF, and 24.42% of PCE, respectively, compared with the without SWCNT device. |
