Figure 4From: Size-controllable synthesis and bandgap modulation of single-layered RF-sputtered bismuth nanoparticlesPlot of ( ahv )1/2vs. ( hv )for the estimation of indirect bandgap of Bi-201 to Bi-206 and Bi-101. The absorption coefficient α is calculated through the optical transmission spectrum. Dashed lines indicate the extrapolation of the data for optical bandgaps. The inset shows the schematic diagram of light passing through a nanoparticle.Back to article page