I. Overview

1.Turning the system on/off

2.Preparing samples

3.Setting up & running a steady state emission experiment

4.Measuring lifetimes with the flash lamp

5.Measuring lifetimes with pulsed lasers

6.Shutdown

II. Turning the system on/off

A. Turning ON

1. Turn on the following, as shown in Fig. FIXME:

a. Power switch for the spectrometer (box PH1)

b. Power switch for the PMT (box CO1)

c. Power switch for the xenon lamp (back of lamp)

d. Press the silver button on the xenon lamp lamp to turn it on.

2. Open the f980 software on the Windows desktop.

B. Turning OFF

1. Turn off the above items in opposite order

2. Turn off the lamp (silver button) but keep the lamp power supply on for an additional 15 minutes to cool down the lamp.

3. Sign the log book, noting the number of minutes the lamp was used.

III. Acquiring steady state emission spectra

1. Load your sample in the appropriate liquid or solid sample holder.

2. For the solid sample holder, attach the translation gear to the knob on the front panel of the sample chamber.

3. Check that the prism on the left side of the chamber has been flipped out of the optical path.

4. Place the lid on the spectrometer.

5. In the software, click on the “Signal Rate” button (icon that looks like 3 bars, left most button on tool bar) to open the Signal Rate window.

a. Set bandwidths ( ) to 1 nm for now to avoid saturating the detector. You can increase these bandwidths later to increase signal.

b. Set your desired excitation wavelengths and the peak emission wavelength.

c. Install an emission filter to remove the excitation but retain the emitted light.

d. In “Source Light Path” drop down menu, select “Xenon Light Path”

e. In “Detector Light Path” drop down menu, select “Standard Range.”

f. Click “Apply”

g. The emission signal should be less than 1,000,000 counts. If the signal is higher than this, you can reduce the signal by:

i. Reducing the emission or excitation slit widths

ii. Installing a neutral density filter in the excitation or emission beam paths.

h. If you are using the solid sample holder, adjust the translation knob on the front of the sample chamber to maximize signal. Again, if the signal is too high, then adjust using slit widths or filters.

i. Click “Apply” and then “Close”

6. Click on the button on the toolbar and then “Emission Scan…” to open the “Emission Scan Setup” window.

a. In the “Emission Scan Parameters” area at the bottom of the window, set the beginning and ending wavelengths as well as the scan step size. You can also set the number of scans to average. The dwell time should be approximately 0.1 s. If you need better signal to noise, then run more scans.

b. In the “Correction” tab, check the boxes for “Excitation Correction” checkbox is checked (select “Recording Ref. Data”), “Emission Correction”, and background correction.

c. To take a spectrum, click “Apply” then “Start.”

IV. Acquiring steady state excitation spectra

1. Click on the “l” button on the toolbar and then “Excitation Scan…” to open the “Excitation Scan Setup” window.

2. Follow a similar routine to that described in the previous section.

3. Check “Recording ref. spectrum” in the Correction box

V. Acquiring luminescent lifetimes with the µs flash lamp (µF2)

1. Turn on the µF2 lamp on the left of the spectrometer.

2. Check that the BNC cable is connected to the “Trigger” input on the back of the lamp.

3. Always acquire a steady state spectrum before proceeding to measure a luminescent lifetime.

4. In the software, click on the “Signal Rate” button (icon that looks like 3 bars, left most button on tool bar) to open the Signal Rate window.

a. Set bandwidths to 0.1 nm for now to avoid saturating the detector. You can increase these bandwidths later to increase signal.

b. Set your desired excitation wavelengths and the peak emission wavelength.

c. In “Source Light Path” drop down menu, select “µF2”

d. In “Detector Light Path” drop down menu, select “MSC.”

e. Click “Apply”

f. The emission signal should be less than 10,000 counts. If the signal is higher than this, you can reduce the signal by:

i. Reducing the emission or excitation slit widths

ii. Installing a neutral density filter in the excitation or emission beam paths.

g. If you are using the solid sample holder, adjust the translation knob on the front of the sample chamber to maximize signal. Again, if the signal is too high, then adjust using slit widths or filters.

h. Click “Apply” and then “Close”

5. Click on the “t” button on the toolbar to open the “Manual measurement” window.

a. In the frame at the bottom of the window, set the Time range to approximately two times the expected lifetime. Channels should almost always be 4096.

b. The minimum lifetime that can be measured of the flash lamp is approximately 2 µs.

c. If you wish, you can set a stop condition of Peak Counts

d. Click “Apply” and then “Start” to start a lifetime acquisition

VI. Acquiring luminescent lifetimes with pulsed lasers

1. Always acquire a steady state spectrum before proceeding to measure a luminescent lifetime.

2. Use of NIR lasers requires specific On-the-Job Training (OJT). Lasers may only be used when fully enclosed. Bypassing interlocks is strictly forbidden. When used correctly, the NIR laser system is a Class 1 system with no special requirements for PPE.

3. By default, the 980-nm laser is installed. If you need to use the 800 nm laser, you MUST ask a superuser to change the laser for you. General users are not allowed to reconfigure laser optics. Reconfiguring lasers without proper authorization has lead to major safety incidents and are grounds for suspension of lab priveleges.

4. In OJT training, an administrator will instruct you how to disconnect the BNC cabling from the µF2 lamp. If the flash lamp sync is connected, the laser will not function properly. Disconnect the BNC cable (thin black cable with large silver connector) at the “Trigger” input of the flash lamp (this is the box to the left of the spectrometer).

5. Flip the prism into the optical path (left side of the sample chamber).

6. Obtaining an emission spectrum with the laser in both CW and pulsed mode, to ensure that the triggering is functioning correctly. Observing the decay of the laser in pulsed mode, adjust the pulse width so that the off time is significantly longer than the expected lifetime of the material.

VII. Troubleshooting

1. Always acquire a steady state spectrum before proceeding to measure a lifetime spectrum.

2. If you observe a sharp decrease in signal around 680nm, or observe a number of sharp peaks from 400—700nm, check that you have installed an emission filter.

3. If you cannot find any signal, check that the prism on the left side of the sample chamber is out of the path (lamp excitation) or in the path (laser excitation).