Quantum Yield

This manual is meant to complement your training and is not intended to replace on-the-job training.

WPC Activities Associated

MF-0001; Work on 4th floor

MF-0007; Fluorolog-3

Training Contact(s)

Tracy Mattox

tmmattox@lbl.gov

67-4111

x2649

Last Updated

10/12/2016

OPERATING PROCEDURE

Quantum Yield Measurements using the Integrating Sphere

Important Notes:

  • Check calibration of the detector BEFORE inserting the integrating sphere!

  • ALWAYS handle integrating sphere with gloves

  • Cover integrating sphere with bag when not in use. If dust and/or sample contaminants get into the sphere it will no longer be usable. Knob must always be at 0° when removing or inserting sample holder into sphere

  • Established QY spreadsheets require emission peaks to end at 700nm or less

  • Only the PMT and CCD detectors are accessible in our configuration

  • All measured intensities must be below 2x106 CPS

Use of the Integrating Sphere

      1. Start-up the system using the standard protocols

      1. Check calibration of gratings using the standard calibration methods, then swap out the sample compartment with the integrating sphere. The set-up only fits one way, and the ISA sticker (serial number) on the sphere must face the front of the instrument.

      1. With the knob set to 0°, press and hold the button on the integrating sphere lid when removing or inserting the sample holder.

      1. Two attachments for samples are available which screw in and out of the sphere lid. Pictured on the left is a holder for 12mm films, and on the right is a holder for specialized cuvettes for solutions. Please be sure that the sample does not touch the lid of the cuvette as it is difficult and often impossible to clean.

      1. When inserting a density filter, place the tab of the filter toward the inside of the sample compartment and let it rest in the filter holder. ­­Choose a filter that ensures the peak intensity does not exceed 2x106 CPS. Dilute the sample if necessary.

      1. Place the lid on top of the sample compartment

      1. Emission scans should be taken in the standard Fluorescence software provided by Horiba. SET BOTH SLIT WIDTHS TO 1

      1. Open the spreadsheet (PLQY) on the desktop and enable macros.

      2. In the Fluorescence software set up your experimental parameters and collect emission scans so that the data matches the spreadsheet you are using. The X and Y data should be copied from the tab titled “Data_S2” and pasted into the Excel spreadsheet following this guidance:

“Scatter” = lamp emission (excitation wavelength) peak

o Requires a filter to keep intensity below 2x106 CPS

“Fluorescence” = sample emission peak

“In-Beam" = knob set to 0°

“Out-of-Beam” = knob set to 90°

“Sphere Only” = no sample in sphere

      1. When all of the data has been inserted into the spreadsheet, open the “Results” tab.

        • Fill in the white boxes for “From” and “To” so that the

          • scatter section includes only the emission peak from the lamp (excitation wavelength)

          • fluorescence section includes only the emission peak from the sample

      1. Look at the bottom of the spreadsheet to view your absorbance and quantum yield results