Measuring the localized surface plasmon resonance effect on large arrays (5 mm × 5 mm) of gold and aluminum nanoparticles on borosilicate glass substrates, fabricated by electron beam lithography

Abstract

Metal nanoparticles have interesting optical properties, in particular, the localized surface plasmon resonance effect (LSPR), which can be used in a range of applications such as photon detectors, photovoltaics, and biosensors. The theory of LSPR is complex, and hence, it is very important to develop reliable model systems, where the properties of the particles can be investigated under controlled conditions. Important parameters, which influence the frequency and intensity of the LSPR, are size, shape, and spacing of the individual nanoparticles, as well as the metal and the surrounding medium. For applications related to photovoltaics, in particular, it is important to investigate the effect of nanoparticles, covering large areas to mimic realistic operating conditions. Here, the authors present a preparation method and optical investigations of LSPR for large arrays (5 mm × 5 mm) of gold and aluminum nanoparticles ranging in diameter from 44 to 140 nm (corresponding to around 120 million particles). The authors compare and see that the LSPR measurements have a good agreement with previously published results from the literature. These measurements from the literature were mostly performed on much smaller arrays. The authors briefly discuss the effect of depositing the nanoparticles on an indium-tin-oxide-coated glass instead of a bare glass substrates and point out an interesting scanning electron microscopy imaging artifact when measuring the samples deposited directly on nonconductive substrates. A shrinkage effect is seen due to sample charging, causing the measured dimensions to appear smaller than the physical size of the object.