Ultrahighly Enhanced Performance of Single Cadmium Selenide Nanobelt by Plasmonic Gold Particles

Abstract

Noble metal nanoparticles have been demonstrated by a huge application prospect for photodetector (PD) due to their unique and tunable optical properties. Herein, a simple strategy is presented by a combination of gold nanoparticles (Au NPs) and broadband photoresponse cadmium selenide nanobelts (CdSe NBs) to get ultrasensitive, broadband photoresponse (300–720 nm) and tunable photoresponse PD. Concretely, the Au NPs are fabricated on CdSe NBs via ion sputtering and annealing, and the morphology of Au NPs is systematically adjusted by simply tuning the sputter time from 60 to 140 s. Compared with the pure CdSe NB PD, the Au NPs hybrid CdSe NB PD exhibits a high responsivity, especially in the range of 525–575 nm with low light intensity (enhancement of ≈2894% at 550 nm with 79.6 μW cm−2). The response time of the hybrid PD is decreased substantially from 0.8 to 0.2 ms. More importantly, the hybrid PD possesses a tunable absorption in the range of 538–580 nm, which is benefited from tunable plasmon resonance of Au NPs. These results are confirmed by the theoretical simulation. It is believed that this strategy offers new opportunities to design ultrasensitive, broadband spectra, and tunable wavelength PD.