Surface plasmon excitation in semitransparent inverted polymer photovoltaic devices and their applications as label-free optical sensors

Abstract

Herein, we report on surface plasmon (SP)-sensitive semitransparent inverted polymer photovoltaic (PV) devices that are based on multilayered material systems consisting of poly(3-hexylthiophene): fullerene-derivative bulk-heterojunction PV layers and thin gold or silver anodes. We demonstrate that these PV devices allow the simultaneous generation of both electrical power and SPs on their anodes for photoexcitation just above the optical absorption edge of the PV layers, resulting not only in attenuated total reflection, but also in attenuated photocurrent generation (APG) under the SP resonance (SPR) condition. Moreover, we also confirm that the biomolecular interaction of biotin–streptavidin on the PV devices can be precisely detected via apparent SPR angle shifts in the APG spectra, even without the need for complex attenuated total reflection configurations. We highlight our view that APG measurements made using these PV devices show great potential for the development of future generations of compact and highly sensitive SPR-based optical sensors. Researchers investigate surface plasmon excitation in photovoltaic devices and explore their application as highly sensitive optical sensors. Byoungchoo Park and co-workers at Kwangwoon University in South Korea have developed semitransparent inverted polymer photovoltaic devices with a planar multilayer structure that are capable of simultaneously generating electrical power and surface plasmons on irradiation. When surface plasmon resonance is induced in these devices, both total internal reflection and photocurrent generation are attenuated. The researchers demonstrated that this property can be exploited to sensitively detect biological compounds. Specifically, they used apparent shifts in the surface plasmon resonance angle in attenuated photocurrent generation to detect the biomolecular interaction of biotin-streptavidin. They conclude that these devices have great potential as next-generation optical sensors that are simple, inexpensive, compact and highly sensitive.