From Inside Out: How the Buried Interface, Shell Defects, and Surface Chemistry Conspire to Determine Optical Performance in Nonblinking Giant Quantum Dots
Ajay Singh,
Somak Majumder,
Noah J. Thompson Orfield,
Ibrahim Sarpkaya,
Dennis Nordlund,
Karen C. Bustillo,
Jim Ciston,
Victoria Nisoli,
Sergei A. Ivanov,
Eric G. Bowes,
Han Htoon,
Jennifer A. Hollingsworth
Affiliations
Ajay Singh
Materials Physics & Applications Division Center for Integrated Nanotechnologies Los Alamos National Laboratory Los Alamos NM 87545 USA
Somak Majumder
Materials Physics & Applications Division Center for Integrated Nanotechnologies Los Alamos National Laboratory Los Alamos NM 87545 USA
Noah J. Thompson Orfield
Materials Physics & Applications Division Center for Integrated Nanotechnologies Los Alamos National Laboratory Los Alamos NM 87545 USA
Ibrahim Sarpkaya
Materials Physics & Applications Division Center for Integrated Nanotechnologies Los Alamos National Laboratory Los Alamos NM 87545 USA
Dennis Nordlund
Stanford Synchrotron Radiation Light Source SLAC National Accelerator Laboratory Stanford CA 94309 USA
Karen C. Bustillo
National Center for Electron Microscopy, Molecular Foundry Lawrence Berkeley National Laboratory 1 Cyclotron Road Berkeley CA 94720 USA
Jim Ciston
National Center for Electron Microscopy, Molecular Foundry Lawrence Berkeley National Laboratory 1 Cyclotron Road Berkeley CA 94720 USA
Victoria Nisoli
Materials Physics & Applications Division Center for Integrated Nanotechnologies Los Alamos National Laboratory Los Alamos NM 87545 USA
Sergei A. Ivanov
Materials Physics & Applications Division Center for Integrated Nanotechnologies Los Alamos National Laboratory Los Alamos NM 87545 USA
Eric G. Bowes
Materials Physics & Applications Division Center for Integrated Nanotechnologies Los Alamos National Laboratory Los Alamos NM 87545 USA
Han Htoon
Materials Physics & Applications Division Center for Integrated Nanotechnologies Los Alamos National Laboratory Los Alamos NM 87545 USA
Jennifer A. Hollingsworth
Materials Physics & Applications Division Center for Integrated Nanotechnologies Los Alamos National Laboratory Los Alamos NM 87545 USA
“Giant” or core/thick‐shell quantum dots (gQDs) are an important class of solid‐state quantum emitter characterized by strongly suppressed blinking and photobleaching under ambient conditions, and reduced nonradiative Auger processes. Together, these qualities provide distinguishing and useful functionality as single‐ and ensemble‐photon sources. For many applications, operation at elevated temperatures and under intense photon flux is desired, but performance is strongly dependent on the synthetic method employed for thick‐shell growth. Here, a comprehensive analysis of gQD structural properties “from the inside out” as a function of shell‐growth method is reported: successive ionic layer adsorption and reaction (SILAR) and high‐temperature continuous injection (HT‐CI), or sequential combinations of the two. Key correlations across synthesis methods, structural features (interfacial alloying, stacking‐fault density and surface‐ligand identity), and performance metrics (quantum yield, single‐gQD photoluminescence under thermal/photo stress, charging behavior and quantum‐optical properties) are identified. Surprisingly, it is found that interfacial alloying is the strongest indicator of gQD stability under stress, but this parameter is not the determining factor for Auger suppression. Furthermore, quantum yield is strongly influenced by surface chemistry and can approach unity even in the case of high shell‐defect density, while introduction of zinc‐blende stacking faults increases the likelihood that a gQD exhibits charged‐state emission.
