Enhancing upconversion quantum yield by means of pulsed excitation modulation

Area of Science:

• Biomedical Engineering
• Materials Science
• Optics

Background:

• Upconversion luminescent nanomaterials are promising for biomedical applications.
• Low quantum yield (QY) limits their effectiveness, especially for in vivo studies.
• Existing methods for QY enhancement have been sub-optimal.

Purpose of the Study:

• To investigate the effect of pulsed-excitation schemes on upconversion luminescence QY.
• To determine optimal pulse-widths for maximizing QY enhancement.
• To provide a method for improving nanomaterial performance in biomedical imaging.

Main Methods:

• Numerical simulations were performed using NaYF4:Yb,Tm as a model material.
• The study focused on analyzing the impact of pulse-width selection on QY.
• The goal was to derive experimental conditions for enhanced QY.

Main Results:

• A simple pulsed-excitation scheme was shown to enhance upconversion luminescence QY.
• Enhancements were observed to be up to several orders of magnitude.
• The selection of prudently chosen pulse-widths was key to the observed QY improvements.

Conclusions:

• Pulsed excitation is an effective strategy for significantly boosting the QY of upconversion nanomaterials.
• This approach offers a viable solution to overcome limitations in current biomedical applications.
• The findings provide a pathway for optimizing experimental conditions for superior nanomaterial performance.