Improved performance of inverted-type organic solar cells by surface modification on polymer thin film
Journal
IEEE Photovoltaic Specialists Conference
Pages
1624-1627
Date Issued
2010
Author(s)
Abstract
Short period plasma exposure on poly(3-hexylthiophene):[6,6]-phenyl C 61 butyric acid methyl ester (P3HT:PCBM) blend film in the inverted bulk-herterojunction (BHJ) solar cells with highly transparent sol-gel derived ZnO film as electron selective layer is studied as a way to improve device performance. This study focuses on the vertical segregation of the two components in polymer thin film during the slow-drying treatment on ZnO substrates and further discovers some drawbacks on the polymer film surface that is unfavorable for carrier transport. With the use of mild plasma exposure, the surface can be modified and forms better penetrating pathways for carriers. The polymer surface adjacent to metal electrode turns into a more hydrophobic P3HT-rich surface which forms better contact, fine electrode selectivity, and lower series resistance in the device. The hole transport in P3HT interpenetrating network avoids recombination at the Ag electrode by the removal of PCBM protrusions. As a result, the current density is improved to 11.75 mA/cm2 and the efficiency is increased to 3.97% with an enhanced fill factor of 62.6%. Our finding provides an efficient method for interface engineering in organic optoelectronic devices and paves a way for high power conversion efficiency for similar structures. © 2010 IEEE.
SDGs
Other Subjects
Ag electrode; Blend films; Butyric acids; Device performance; Drying treatment; Efficient method; Fill factor; High power conversion; Hole transports; Interface engineering; Interpenetrating networks; Metal electrodes; Methyl esters; Organic optoelectronics; Organic solar cell; Plasma exposure; Poly (3-hexylthiophene); Polymer surfaces; Polymer thin films; Selective layers; Series resistances; Short periods; Surface modification; Transparent sol; Two-component; Vertical segregation; ZnO films; ZnO substrate; Conversion efficiency; Esters; Fatty acids; Optoelectronic devices; Photovoltaic effects; Plastic films; Polymer films; Polymeric films; Polymers; Solar cells; Thin films; Zinc oxide; Surface segregation
Type
conference paper