應用於染料敏化太陽能電池對電極之鉑-聚(3,4-乙烯基二氧噻吩)/聚(苯乙烯磺酸鹽)導電奈米複合薄膜的製備與性質分析

Preparation and Characterization of PEDOT:PSS-Pt Conducting Nano-Composite Film for the Application of Counter Electrode of Dye Sensitized Solar Cell

江明泰(Ming-Tai Jiang)

指導教授 ： 張正良

共同指導教授 ： 張朝欽

淡江大學/工學院/化學工程與材料工程學系碩士班/碩士(2010年)

https://doi.org/10.6846/TKU.2010.00103

摘要

本論文染料敏化太陽能電池，使用N719染料-TiO2工作電極、碘離子電解液與白金對電極光電轉換效率可達3.2%，然而染料敏化太陽能電池使用奈米白金混摻導電高分子PEDOT:PSS導電奈米複合薄膜對電極已可得光電轉換效率3.02%。藉由循環伏安法，比例為22Wt%奈米白金於PEDOT:PSS導電高分子中且經1200C， 20分鐘熱處理，厚度為450 nm之導電奈米複合薄膜對其碘離子電解液有最佳氧化還原特性。由SEM與AFM可發現具有表面孔洞的導電奈米複合薄膜與粗糙度的增加，皆可提升PEDOT:PSS-Pt導電奈米複合薄膜對碘離子電解液的氧化還原能力。熱處理最佳化是必須的,過高溫之熱處理會破壞PEDOT:PSS庫倫作用力而使導電度下降，過低溫熱處理將無法完全移除溶劑。同樣地，膜厚也影響PEDOT:PSS-Pt導電奈米複合薄膜對電極氧化還原表現，藉由極化曲線可得知較厚之導電奈米複合薄膜具有較高面電阻值，然而膜厚較薄之導電奈米複合薄膜又易出現pin hole。22Wt%奈米白金於PEDOT:PSS奈米複合薄膜再經由交流阻抗分析證實其對碘離子電解液具有最小之電子交換阻抗。最後經由電化學Randles-Sevcik法證實PEDOT:PSS-Pt導電奈米複合薄膜對碘離子的氧化還原為質傳控制，代表碘離子的氧化還原速率決定步驟為碘離子之本身擴散。
染料敏化太陽能電池使用PEDOT:PSS-Pt導電奈米複合薄膜對電極其開路電壓發現有下降之趨勢當使用22Wt%奈米白金於PEDOT:PSS奈米複合薄膜中，其可歸因於質傳過電壓損失與電子交換過電壓損失之存在，當短路電流相對提升時，由歐姆定律可得知其過電壓損失昰增加的。填充因子有增加的趨勢，當奈米白金量的使用量增加時，這與 PEDOT:PSS-Pt導電奈米複合薄膜面電阻質之改善有關。

關鍵字

染料敏化太陽能電池

並列摘要

The application of the platinum nanoparticles added in PEDOT:PSS conducting polymer as the counter electrode for DSSC, which was made by depositing PEDOT:PSS-Pt on FTO substrate by spin coating method, following the low temperature heat process was conducted, and thus the PEDOT:PSS-Pt counter electrode assembled with N719-TiO2 photo-electrode and employed I-/I3- mediator as electrolyte. The heat process and film thickness influence the PEDOT:PSS-Pt counter electrode electrocatalytical activity significantly. The thickness 450 nm of conductive PEDOT:PSS matrix contained 22 wt% platinum nanoparticles after 120 0C heat process exhibited best photo-conversion efficiency 3.02% under Am 1.5 illumination in comparison with the device assembled with thermal decomposition of H2PtCl6 counter electrode which photo-conversion efficiency 3.2% was obtained. The SEM and AFM images proved that the presence of pores and the increased surface roughness enhancing the cell performance remarkably. Impedance measurement demonstrated that the charge transfer resistance was improved as increasing the amount of platinum nanoparticles. Additionally, the diffusion control was also confirmed when use of the PEDOT:PSS-Pt counter electrode in I-/I3- mediator electrolyte by Randles-Sevcik method.
In this work, the material cost and energy-consuming of PEDOT:PSS-Pt counter electrode were drastically reduced compared with the thermal decomposition of H2PtCl6 counter electrode. The DSSC using PEDOT:PSS-Pt counter electrode had obtained acceptable performance, which suggested that the nanocomposite film PEDOT:PSS-Pt is a promising candidate to replace of the platinum for DSSC counter electrode and to develop a bifacial flexible DSSC.

並列關鍵字

PEDOT:PSS

參考文獻

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