Importance of interface engineering between hole transport layer and indium tin oxide in polymer solar cells
발표자
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초록
내용
In early studies on organic solar cells with high conductivity PEDOT:PSS, the contact between ITO and PEDOT:PSS was considered ohmic. However, because low-conductivity PEDOT:PSS (such as AI4083) is mainly utilized in contemporary solar cells, the contact between ITO and PEDOT:PSS is not ohmic anymore. Despite the high possibility of severe interface problems, little attention has been paid to the interface between PEDOT:PSS and ITO. In this work, we have employed a conjugated polyelectrolyte that uses potassium poly[9,9-bis(3′-sulfonatopropyl)fluorene-alt-(9-(2,7-diethylheptyl)-carboazole)] (WPFSCz-) between ITO and low-conductivity PEDOT:PSS to overcome complicated organic-inorganic interfacial problems. The inserted WPFSCz- layer eliminates interfacial trap sites and modifies the work-function of ITO, thereby forming an effective cascading energy alignment, which is favorable for good hole transport. These effects result in a significant increase in the efficiency of non-fullerene solar cells based on PM6 and Y6, from 15.86 to 17.34%.