Development of the Morphology during Functional Stack Build-up of P3HT:PCBM Bulk Heterojunction Solar Cells with Inverted Geometry
2015 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 7, no 1, 602-610 p.Article in journal (Refereed) Published
Highly efficient poly(3-hexylthiophene-2,5-diyl) (P3HT):phenyl-C61-butyric acid methyl ester (PCBM) bulk heterojunction solar cells are achieved by using an inverted geometry. The development of the morphology is investigated as a function of the multilayer stack assembling during the inverted solar cell preparation. Atomic force microscopy is used to reveal the surface morphology of each stack, and the inner structure is probed with grazing incidence small-angle X-ray scattering. It is found that the smallest domain size of P3HT is introduced by replicating the fluorine-doped tin oxide structure underneath. The structure sizes of the P3HT:PCBM active layer are further optimized after thermal annealing. Compared to devices with standard geometry, the P3HT:PCBM layer in the inverted solar cells shows smaller domain sizes, which are much closer to the exciton diffusion length in the polymer. The decrease in domain sizes is identified as the main reason for the improvement of the device performance.
Place, publisher, year, edition, pages
2015. Vol. 7, no 1, 602-610 p.
P3HT PCBM, BHJ solar cell, inverted solar cell, GISAXS, morphology
Textile, Rubber and Polymeric Materials
IdentifiersURN: urn:nbn:se:kth:diva-161139DOI: 10.1021/am5067749ISI: 000348085200072PubMedID: 25495375ScopusID: 2-s2.0-84921289931OAI: oai:DiVA.org:kth-161139DiVA: diva2:796629
QC 201503192015-03-192015-03-092015-03-19Bibliographically approved