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

Enhancement of Terahertz Radiation by Surface Plasmons Based on CdTe Thin Films

“…Although thicker CdTe can effect better Raman signals, weakened SPP enhancement leads to totally decreased Raman intensity. Thus, it can be concluded that SPPs enhancement plays a key role in Raman scattering, where SPPs can generate the intense electric field to improve the optical signal of nearby materials [27]. Furthermore, SPPs are equally important for the enhancement of THz radiation; a similar variation trend can be observed in THz spectroscopy (Figure 3c).…”

“…Since both the quantity of evaporated CdTe and the surface plasmon enhancement contributed to the Raman intensity [25,27], Raman mapping images of ~5, ~10, and ~15 nm thick CdTe on the AuAg alloy films were collected and displayed in Figure 4 for further analysis, upon which 122 and 164 cm −1 were selected as the center wavenumbers. We observed that CdTe of ~10 nm thickness was more evenly coated on the substrate and the average strength was stronger.…”

“…The thin CdTe film a thickness of ~10 nm on the AuAg alloy was used for further THz wave measurement. When 780 nm laser pulses [27] illuminate the CdTe10@AuAg surface at an oblique incidence at 45 • , ultrafast photocurrents are generated. These photocurrents consist of nonlinear currents (J nl ), drift currents (J dri ) and diffusion currents (J di f ), which can be distinguished via THz emission signal.…”