Disordered plasmonic nanocavity enhanced quantum dot emission

In this paper, a large-scale compatible plasmonic nanocavity design platform is utilized to achieve a nearly order of magnitude photoluminescence (PL) enhancement. The proposed design is made of multi-sized/multi-spacing gold (Au) nanounits that are uniformly wrapped with a thin aluminum oxide (Al2O3) layer, as a foreign host to form a metal-insulator-semiconductor cavity, as they are coated with semiconductor quantum dots (QDs). Our numerical and experimental data demonstrate that, in an optimal insulator layer thickness, the simultaneous formation of broadband Fabry-Perot resonances and plasmonic hot spots leads to enhanced light absorption within the QD unit. This improvement in absorption response leads to the PL enhancement of QDs. This work demonstrates the potential and effectiveness of a random plasmonic nanocavities host in the realization of lithography-free efficient emitters.

Automated summary

In this paper, a large-scale compatible plasmonic nanocavity design platform is used to achieve a nearly tenfold increase in photoluminescence (PL) enhancement. The design consists of multi-sized/multi-spacing gold (Au) nanounits wrapped in a thin aluminum oxide (Al2O3) layer to form a metal-insulator-semiconductor cavity, with semiconductor quantum dots (QDs) coated on top. Numerical and experimental data show that, with an optimal insulator layer thickness, the simultaneous formation of broadband Fabry-Perot resonances and plasmonic hot spots enhances light absorption within the QD unit, leading to the PL enhancement of QDs. This work demonstrates the potential and effectiveness of a random plasmonic nanocavities host in achieving lithography-free efficient emitters.