Electron accumulation on metal nanoparticles in plasmon-enhanced organic solar cells.
Plasmonic metal nanoparticles have been used to enhance the performance of thin-film devices such as organic photovoltaics based on polymer/fullerene blends. We show that silver nanoprisms accumulate long-lived negative charges when they are in contact with a photoexcited bulk heterojunction blend composed of poly(3-hexylthiophene)/phenyl-C61-butyric acid methyl ester (P3HT/PCBM). We report both the charge modulation and electroabsorption spectra of silver nanoprisms in solid-state devices and compare these spectra with the photoinduced absorption spectra of P3HT/PCBM blends containing silver nanoprisms. We assign a previously unidentified peak in the photoinduced absorption spectra to the presence of photoinduced electrons on the silver nanoprisms. We show that coating the nanoprisms with a 2.5 nm thick insulating layer can completely inhibit this charging. These results may inform methods for limiting metal-mediated losses in plasmonic solar cells.
Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States.
Michael
M
Salvador
Bradley A
BA
MacLeod
Angela
A
Hess
Abhishek P
AP
Kulkarni
Keiko
K
Munechika
Jennifer I L
JI
Chen
David S
DS
Ginger
D011211:Electric Power Supplies; D004579:Electron Transport; D004867:Equipment Design; D019544:Equipment Failure Analysis; D037741:Fullerenes / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation*; D016566:Organoselenium Compounds / Q000737:chemistry*; D012993:Solar Energy; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
C551883:1-(3-methoxycarbonyl)propyl-1-phenyl-(6,6)C61; D037741:Fullerenes; D016566:Organoselenium Compounds; C526212:poly(3-hexyl)selenophene