title: Direct probe of spectral inhomogeneity reveals synthetic tunability of single-nanocrystal spectral linewidths.
abstract: The spectral linewidth of an ensemble of fluorescent emitters is dictated by the combination of single-emitter linewidths and sample inhomogeneity. For semiconductor nanocrystals, efforts to tune ensemble linewidths for optical applications have focused primarily on eliminating sample inhomogeneities, because conventional single-molecule methods cannot reliably build accurate ensemble-level statistics for single-particle linewidths. Photon-correlation Fourier spectroscopy in solution (S-PCFS) offers a unique approach to investigating single-nanocrystal spectra with large sample statistics and high signal-to-noise ratios, without user selection bias and at fast timescales. With S-PCFS, we directly and quantitatively deconstruct the ensemble linewidth into contributions from the average single-particle linewidth and from sample inhomogeneity. We demonstrate that single-particle linewidths vary significantly from batch to batch and can be synthetically controlled. These findings delineate the synthetic challenges facing underdeveloped nanomaterials such as InP and InAs core-shell particles and introduce new avenues for the synthetic optimization of fluorescent nanoparticles.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Jian
authors.initials: J
authors.lastname: Cui
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Beyler
authors.forename: Lisa F
authors.initials: LF
authors.lastname: Marshall
authors.forename: Ou
authors.initials: O
authors.lastname: Chen
authors.forename: Daniel K
authors.initials: DK
authors.lastname: Harris
authors.forename: Darcy D
authors.initials: DD
authors.lastname: Wanger
authors.forename: Xavier
authors.initials: X
authors.lastname: Brokmann
authors.forename: Moungi G
authors.initials: MG
authors.lastname: Bawendi
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry; D053758:Nanoparticles; D018036:Selenium Compounds / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013440:Sulfides / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D018036:Selenium Compounds; D013440:Sulfides; C034939:cadmium sulfide; C058667:cadmium selenide