Spectroscopic Signatures of Plasmon-Induced Charge Separation in Gold Nanorods on Metal-Oxide Semiconductors

Tuesday, March 09, 2021: 9:10 AM - 9:30 AM

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Description

Plasmon-induced charge separation, the process by which a plasmon decays into spatially separated hot-carriers, has been studied for the development of plasmonic photodiodes and solar cells. Current methods for evaluating the efficiency of a plasmon-induced charge separation device rely on having completed photodevices and are based on the bulk characteristics of the device. Here, we use single-particle darkfield scattering and photoluminescence spectroscopy and imaging to identify key spectroscopic signatures that are quantitatively related to plasmon-induced charge separation device efficiency. We identify darkfield scattering linewidth broadening and photoluminescence quantum yield quenching as two spectroscopic signatures for indirectly predicting the plasmon-induced charge separation efficiency. We find that darkfield scattering linewidth broadening is due to chemical interface damping through charge injection. The photoluminescence quantum yield quenching is indicative of space-charge separation efficiency and related to Schottky barrier formation in Au-TiO2 interfaces but not in Au-ITO interfaces. Through these two spectroscopic signatures we can determine the contributions of different plasmon-induced charge separation device factors on performance such as Schottky barrier formation and height, plasmonic nanoparticle size, and effects of electron/hole transport materials prior to fabricating a completed device.

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Additional Info

Keywords: Please select up to 4 keywords ONLY:
Light Scattering,Physical Measurements,Nanoscience,Particle Characterization