(Invited) Photocurrent Generation of PbS Nanopartciles with Narrower Bandgap Coupled with Localized Surface Plasmon Resonance

Abstract

Confined photon field generated by localized surface plasmon resonance could provide the chance to excite electrons in materials via exotic routes. Coupling with tunable electronic structures leads to successful tuning for electrochemical potentials of excited electrons/holes. We know that PbS quantized dots (PbS QDs) sensitized photocurrent generation system has been proved to be one of the promising candidates for next photoenergy devices owing to valuable tuning of the band gap via quantization because of relatively large Bohr radius of 18 nm due to its metallic properties. By well coupling with Au NPs, PbS QDs are able to enhance the localized electric field generated by Au NPs and consequently uplift the photoelectric conversion across a wide visible light region. In this work, photocurrent of size-controlled PbS QDs with the sizes from 2.3 nm to 4.8 nm excited by localized surface plasmon resonance was observed to determine the effect of photoexcitation, especially at the energy two times higher that PbS QDs’ bandgap.