Improved optical absorption by local surface plasmon resonance of silver nanoparticles in nanocolumnar CdTe thin films

Cadmium telluride (CdTe) thin films with a nanocolumnar morphology were grown on glass substrates using the Sublimated Vapor Effusion Deposition technique and a rotational source in counter-rotation with respect to the substrate. Afterward, it was proceeded to coat with silver nanoparticles whose average size was of similar to 100 +/- 40 nm. X-ray diffraction analysis showed that all samples presented the zinc-blend structure with a preferred orientation of (111), with a crystallite size of similar to 52 nm, and that they were under tensile stress. The bandgap value was E-G = 1.53 eV and the Urbach energy E-0 similar to 13.2 meV. The porosity value was estimated at similar to 0.0562 (5.6%). A Localized Surface Plasmon Resonances effect was presented for the Ag nanoparticles near the wavelengths close to 548 nm and 660 nm, and this resulted in improved light absorption in the CdTe nanocolumnar layer compared to samples grown only with a CdTe nanocolumnar structure.