Using EDS measurements the chemical composition of several indium islands on a single sample have been determined. Before the sample Embelin prepared for TEM and EDS measurements the sample is coated with carbon and platinum to protect the sample during processing of the TEM slice. As shown in Fig. 3(a), a color map showing the indium (red), gallium (green), arsenic (violet), and oxygen (yellow) mapping of a single island, the indium islands are predominantly indium. A TEM of the island with the sample structure outlined is shown in Fig. 3(b). In the dashed outline in the central area of the indium island in Fig. 3(a), representing a 20 nm by 10 nm section of the island, the indium concentration was measured to be 89.9% with only 5.6% gallium and 4.5% arsenic. Despite the presence of gallium and arsenic in the islands and an oxide layer covering the island the samples show a strong plasmonic resonance as shown in Fig. 2.
Fig. 3. (a) An EDS map of an island showing that lymphatic system is predominantly indium (red) but also contains arsenic (violet), gallium (green), and oxygen (yellow). The white dashed box represents a 20 nm by 10 nm region where an indium concentration of 89.9% was measured. (b) A TEM image of the same island with the different regions of the structure outlined and labeled. (For interpretation of the references to color in this figure, the reader is referred to the web version of this article.)Figure optionsDownload full-size imageDownload as PowerPoint slide