One-pot controlled microwave synthesis of Broadband-light absorbing irregular gold nanoparticles for solar cell application

Abstract

Improvement of light-harvesting efficiency using the localized surface plasmon resonance (LSPR) from the metals nanoparticles (MNPs) is a promising approach to boost the efficiency of the solar energy conversion systems. To attain the narrowband SPR, synthesis of the monodisperse MNPs with particular shapes and sizes is cumbersome and has great importance for (surface-enhanced Raman spectroscopy) SERS application. Contrary, broadband SPR is prominent for solar cell applications to absorb maximum sunlight from the solar spectrum. Incorporating polydisperse MNPs of mixed shapes and sizes is a unique approach to realizing the broadband SPR for solar cell application. However, the synthesis of polydisperse MNPs with good reproducibility is challenging. To address this issue, we report facile one-pot microwave synthesis of mixed shapes and sizes of Au nanoparticles (Au-Mx), possessing broadband SPR with decent reproducibility. Microwave-assisted uniform heating provides the control over the reaction parameter to produce identical SPR. Further, the light-harvesting ability of the Au-Mx is demonstrated by incorporating ∼ 1% of Au-Mx in photoanode while fabricating the dye-sensitized solar cells (DSSCs). The photoconversion efficiency (PCE) of the Au-Mx loaded DSSCs improved by ∼ 30% compared to the reference devices, indicating the effective utilization of broadband SPR for efficient charge generation in plasmonic devices.