Suppressed Blinking under Normal Air Atmosphere in Toxic-Metal-Free, Small Sized, InP-Based Core/Alloy-Shell/Shell Quantum Dots

Suppressed blinking has been reported in large (diameter similar to 14.1 nm) core/shell InP quantum dots (QDs) under reduced air environment. We report here suppressed blinking with approximately four times smaller (diameter, similar to 3.6 nm) core/alloy-shell/shell InP QDs under ambient air atmosphere. The < ON fraction > has been obtained to be 0.65. Approximately 26% of the single QDs exhibit ON fraction >80%. The smaller ON exponent (1.19) magnitude in comparison to the OFF exponent (1.45) indicates longer ON events are interrupted by smaller OFF events. ON event truncation time is similar to 1.5 times that of the OFF event, signifying the detrapping rate is much higher than the trapping rate. Interestingly, the detrapping rate/trapping rate (single-particle level property) could be directly correlated to the photoluminescence quantum yield (ensemble level property). An additional exponential term required to fit the probability density distribution of the ON event duration could be correlated with hole trapping, leading to extended ON times (>60 s).