Description

Short wavelength infrared (SWIR) emitting quantum dots (QDs), such as PbS, PbSe, and InAs have many potential applications, however, sample heterogeneity can severely limit their utility. Therefore, methods are needed to characterize the properties of individual QDs. In the visible, avalanche photodiodes have enabled the study of the emission photon stream of single nanocrystals. This information has led to advances in understanding fluorescent intermittency, core-shell structures, biexciton quantum yield and spectral diffusion. One example, Photon Correlation Fourier Spectroscopy (PCFS), enables researchers to extract the spectral correlation of a single nanocrystal, yielding information about individual particle lineshapes and spectral diffusion. We apply PCFS to SWIR emitting QDs. Utilizing superconducting nanowire single photon detectors, which are sensitive to single dot emission from 1 to 1.8 microns we probe PbS quantum dots, revealing single emitter lineshapes evaluating different QD synthetic strategies.

Speaker(s):

• Justin Caram, MIT