Overview
IEC TS 62607-3-3:2020 defines a standardized method for measuring the fluorescence lifetime of semiconductor quantum dots (QDs) using time correlated single photon counting (TCSPC). This Technical Specification applies to liquid samples that are stable dispersions of QDs (not solid samples) and covers the full workflow: experimental procedures, data processing and a case study. TCSPC in this standard is suitable for fluorescence lifetime measurements in the picoseconds to nanoseconds range.
Key topics and requirements
- Test principle: Use of TCSPC to build a histogram of photon arrival times after repetitive pulsed excitation to derive fluorescence decay curves.
- Sample scope: Only liquid, stable QD dispersions; solid-state samples are excluded.
- Measurement equipment: TCSPC fluorescence spectrometer with appropriate pulsed laser excitation and single-photon detectors; instrumentation must support high repetition-rate excitation to accumulate photon statistics.
- Measurement procedure:
- Instrument preparation and alignment
- Fluorescence lifetime decay curve acquisition
- Instrumental response function (IRF) measurement
- Data fitting and analysis (decay deconvolution, lifetime extraction)
- Data handling: Procedures for processing decay curves, fitting models (single/multi-exponential where applicable), and reporting results.
- Reporting and uncertainty: Required test report elements and identification of major uncertainty sources for traceable lifetime values.
- Supporting material: Informative annexes including a practical case study and examples of laser excitation sources used in TCSPC.
Applications and who uses it
IEC TS 62607-3-3 is important for organizations and professionals working with luminescent nanomaterials and semiconductor quantum dots, including:
- Nanomaterials manufacturers performing quality control and process validation
- R&D laboratories characterizing optical properties of QDs for LEDs, displays, lasers, and bioimaging
- Metrology and standards laboratories establishing traceable fluorescence lifetime measurements
- Instrument manufacturers and service labs calibrating TCSPC systems
Measuring fluorescence lifetime provides environment- and structure-sensitive information that is largely independent of concentration or excitation intensity, making it valuable for evaluating solvent effects, quenching, molecular interactions, and kinetic processes in QD dispersions.
Related standards
- IEC 62607 series - Nanomanufacturing – Key control characteristics (other parts)
- ISO 3696 - Water for analytical laboratory use
- ISO 385, ISO 648, ISO 1042 - Laboratory glassware standards cited for sample preparation
Keywords: IEC TS 62607-3-3, fluorescence lifetime, TCSPC, quantum dots, luminescent nanomaterials, semiconductor QDs, time correlated single photon counting, IRF, nanomanufacturing