Reinforcing the Built‐In Field for Efficient Charge Collection in Polymer Solar Cells. (8th January 2018)

• Record Type: Journal Article
• Authors: Lee, Jong‐Hoon; Jeong, Song Yi; Kim, Geunjin; Park, Byoungwook; Kim, Junghwan; Kee, Seyoung; Kim, Bongseong; Lee, Kwanghee
• Is Part Of: Advanced functional materials. Volume 28:Number 10(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-01-08
• Subjects: built‐in electric field -- charge transport layers -- electric dipole layers -- interface engineering -- polymer solar cells; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201705079
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: The collection efficiency of photogenerated charges in polymer solar cells (PSCs) is strongly influenced by the built‐in field ( E in ) that develops across the photoactive materials. Here, by investigating the E in ‐development regimes in PSCs by introducing two types of interlayers, electric dipole layers (EDLs) and charge transport layers (CTLs), the device architecture is optimized to result in a larger E in . By incorporating a pair of EDLs on both sides of the photoactive layer, the E in is modulated by shifting the vacuum energy at each metal–semiconductor interface, providing a larger E in than that in conventional PSCs using typical CTLs, such as metal oxides and/or conducting polymers. These devices using paired EDLs exhibit an average PCE of 9.8%, which far surpasses the average PCE of ≈8.5% for paired CTLs. Abstract : Polymer solar cells with a new device architecture for reinforcing built‐in electric field is demonstrated. A pair of strong electric dipole layers on both sides of the photoactive layer maximizes internal electric field in the operating state under short circuit condition, which permits an efficient "sweep out" of photo generated charges compared to those of typical charge transport layers.