Tunable plasmonic hot carrier dynamics in noble metal alloys

Noble metal alloys exhibit promise as a tunable plasmonic material with an 'on-demand optical response' [1]. However, the performance of these metal alloys for plasmonic hot carrier harvesting remains unknown. In particular, disorder in the alloys is expected to lead to increased scattering and inhibit transport of low energy carriers in metal alloys, but the corresponding situation for hot carriers is not yet known. Moreover, hot carrier generation and injection across a metal-semiconductor interface depend sensitively on the band structure [2], and alloys may provide an opportunity to tune the band structure for increasing injection. This talk will present first-principles predictions of hot carrier generation and transport properties of ordered and random structures of gold-silver alloys. The density of states and phase space for both optical excitation and hot carrier scattering depend critically on composition and disorder, providing an additional knob for generating and harvesting hot carriers with desired energy distributions.

[1] L. M. S. Gong, Chen, ACS Photonics 3, 507 (2016).
[2] A. Habib, F. Florio, and R. Sundararaman, J. Opt. 20, 064001 (2018).