Surface Normal Lasing from CdSe Nanoplatelets Coupled to Aluminum Plasmonic Nanoparticle Lattices
Nicolas E. Watkins, Jun Guan, Benjamin T. Diroll, Kali R. Williams, Richard D. Schaller, Teri W. Odom
Abstract
This paper describes low-threshold lasing from colloidal CdSe nanoplatelets (NPLs) coated on two-dimensional plasmonic cavities composed of aluminum nanoparticles (NPs). We designed the NP lattice to support a spectrally narrow surface lattice resonance whose wavelength overlapped with the amplified spontaneous emission (ASE) from CdSe NPLs. Al NP lattices coated with CdSe NPL thin films were optically pumped and exhibited lasing in the surface normal direction with low angular divergence, narrow spectral line width (∼1 nm), and a threshold of ∼200 μJ/cm2. Nonlinear light emission characteristics were found to depend on the thickness of the CdSe NPL film. A minimum thickness of 150 nm was required to observe SLR-mediated lasing, but thinner films exhibited only photoluminescence. Films above 150 nm exhibited both in-plane waveguided ASE from the CdSe NPL film and lasing action from the Al NP lattice.