Letter pubs.acs.org/NanoLett
Measurement of Emission Lifetime Dynamics and Biexciton Emission Quantum Yield of Individual InAs Colloidal Nanocrystals Thomas S. Bischof,† Raoul E. Correa,† Danna Rosenberg,‡ Eric A. Dauler,‡ and Moungi G. Bawendi*,† †
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02420, United States
‡
S Supporting Information *
ABSTRACT: The understanding of the photophysics of visibleemitting colloidal nanocrystals (NCs) has long been aided by single-molecule studies of their emission. Until recently, no suitable detection technologies have existed for corresponding studies of shortwave-infrared (SWIR) emitters. Now, the use of superconducting nanowire single-photon detectors (SNSPDs) enables the detailed study of SWIR NC emission dynamics at the singleemitter level. Here, we report a detailed analysis of the emission dynamics of individual InAs/CdZnS NCs emitting in the SWIR region. We observe blinking akin to the type A and type B blinking previously observed in visible-emitting CdSe NCs. We determine the intrinsic radiative lifetime of several InAs/CdZnS NCs and find examples ranging from 50−200 ns, indicative of a quasi-type-II electronic structure. We also measure g(2) 0 for several of these NCs and find that their biexciton emission quantum yields vary from
