title: A pronounced dispersion effect of crystalline silicon nanoparticles on the performance and stability of polymer:fullerene solar cells.
abstract: We investigated the dispersion effect of crystalline silicon nanoparticles (SiNP) on the performance and stability of organic solar cells with the bulk heterojunction (BHJ) films of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C(61)-butyric acid methyl ester (PC(61)BM). To improve the dispersion of SiNP in the BHJ films, we attached octanoic acid (OA) to the SiNP surface via esterification reaction and characterized it with Raman spectroscopy and high-resolution transmission electron microscopy. The OA-attached SiNP (SiNP-OA) showed improved dispersion in chlorobenzene without change of optical absorption, ionization potential and crystal nanostructure of SiNP. The device performance was significantly deteriorated upon high loading of SiNP (10 wt %), whereas relatively good performance was maintained without large degradation in the case of SiNP-OA. Compared to the control device (P3HT:PC(61)BM), the device performance was improved by adding 2 wt % SiNP-OA, but it was degraded by adding 2 wt % SiNP. In particular, the device stability (lifetime under short time exposure to 1 sun condition) was improved by adding 2 wt % SiNP-OA even though it became significantly decreased by adding 2 wt % SiNP. This result suggests that the dispersion of nanoparticles greatly affects the device performance and stability (lifetime).
authors.affiliation: Organic Nanoelectronics Laboratory, Department of Chemical Engineering, and §Research Institute of Advanced Energy Technology, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors.forename: Joonhyeon
authors.initials: J
authors.lastname: Kim
authors.forename: Seungsoo
authors.initials: S
authors.lastname: Lee
authors.forename: Sungho
authors.initials: S
authors.lastname: Nam
authors.forename: Hyena
authors.initials: H
authors.lastname: Lee
authors.forename: Hwajeong
authors.initials: H
authors.lastname: Kim
authors.forename: Youngkyoo
authors.initials: Y
authors.lastname: Kim
mesh_terms: D002210:Caprylates / Q000737:chemistry; D037741:Fullerenes / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D012993:Solar Energy; D013876:Thiophenes / Q000737:chemistry
chemical_list: C539575:(6,6)-phenyl C61-butyric acid methyl ester; D002210:Caprylates; D037741:Fullerenes; D011108:Polymers; D013876:Thiophenes; C507295:poly(3-hexylthiophene); C031492:octanoic acid; D012825:Silicon