| Summary: | 碩士 === 國立勤益科技大學 === 化工與材料工程系 === 103 === Graphene exhibits good electron conductivity, thermal conductivity and strength. Graphene may become the new electron conductivity material in place of silicon in the future. Graphene may be used for flexible display and polymer solar cell due to its conductivity, transparent and toughness.
In this study, we used reduced graphene oxide (r-GO, reduced-GO)、nickel oxide (NiOx) and oleic acid silver (OA-Ag) as the hole transport layer (HTL) of polymer solar cells. We studied the effect of different layer and reduction temperature on the characteristics of polymer solar cells. The structures of solar cell were three types of (A) ITO / r-GO(1.0 mg / ml, 1 ~ 3 layers)/P3HT: PC61BM / Ca / Al, (B) ITO / r-GO / NiOx(0.5M, 1 ~ 3 layers) / P3HT: PC61BM / Ca / Al, and (C) ITO / r-GO / NiOx / OA-Ag (1.0 mg / ml, 1 ~4 layers)/ P3HT: PC61BM / Ca / Al。
We used the UV-Vis, PL, SPM, SEM to measure the absorbance, radiation fluorescence intensity, surface roughness and morphology, respectively. We used the solar simulator to measure J-V characteristic and power conversion efficiency of the device.
When the HTL of cell was two layers of r-GO (r-GO-2) and reduced at 250℃ in the structure (A). The cell exhibited the highest power conversion efficiency of 2.07 %.
When the HTL of cell was two layers of r-GO and two layers of NiOx (r-GO-2/NiOx-2) in the structure (B). The cell exhibited the highest short-circuit current density of 8.34 mA/cm2 and power conversion efficiency of 2.93 %. When compared to structure (A), the short-circuit current density was increased from 6.23 mA/cm2 to 8.34 mA/cm2, an increase of 33.9 %. The power conversion efficiency was increased from 2.07 % to 2.93 %, an increase of 41.5 %. From these results, adding the nickel oxide on the r-GO as hole transport layer can increase the short-circuit current density and power conversion efficiency of the polymer solar cells.
Reduced graphene oxide, nickel oxide, and oleic acid silver were used as HTL in the structure (C). The cell had the highest short-circuit current density and power conversion efficiency when its HTL was r-GO-2/NiOx-2/OA-Ag-3. When compared to structure (B), the short-circuit current density was increased to 9.11 mA/cm2, an increase of 9.2 % and the power conversion efficiency was increase to 3.45 %, an increase of 17.7 %. From these result, we found that adding oleic acid silver onto the r-GO/NiOx HTL can increase the short-circuit current density and power conversion efficiency of the polymer solar cell. The structure (C) exhibits the better performance than those of structure (A) or structure (B).
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