Time-resolved photoluminescence (english version)

(update February 28th  2023)

Person in charge

Florian MASSUYEAU

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Principle :

Based on the luminescence of a sample, this technique detects precisely its temporal evolution according to an ultrafast excitation.

It brings information on excited states, its radiative transitions but also its non-radiative transitions. Luminescence decays reveal the dynamic of the photogenerated species: lifetime, excitonic migration, mechanism of charge/energy transfer, bimolecular interaction (e.g. exciton-exciton annihilation).

Different strategies have been proposed to temporally resolve the photoluminescence signature. At IMN, the setup use a streak camera to obtain 3-dimensionnal images (time, wavelength and PL intensity).
Every kind of samples can be observed: solution, powder, thin film, gemstone.

3D-image obtained on a PPV thin film (time window: 1 ns or 1000 ps). The fluorescence intensity is based on a color scale from blue (minimum) to red (maximum). The CCD record the spectrum on a 300 nm range. Excitation : 400 nm.

 

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Equipments :

The home-made setup record 3D images in the UV-Vis range (from 270 to 800 nm) and in a temporal range from 1ns to 1ms. Non-temporally-resolved measurements are recorded thanks to an IRCCD InGaAs from (800-1700 nm). This setup is basically divided in two parts: the pulsed excitation to generate the transient photoluminescence signature and the detection to collect this signal.

Scheme of the home-made time-resolved photoluminescence setup at IMN.

Pictures of the setup at IMN

- Excitation part

• • Femtosecond laser, 1 kHz, Hurricane X Spectra-Physics (pulse duration: 100 fs, 800nm, 1W) ;
  • OPA and SHG/THG Spectra-Physics.
    
     
     

- Detection part

• • SDG II Spectra physics, delay generator for the 0.5 ns-100 ns range;
  • DG535 Stanford Research Systems, delay generator for the 100 ns-1 ms range ;
  • Acton Princeton Instrument SP 2360 spectrometer ;
  • CCD NIR Princeton Instrument OMA V ;
  • Streak camera Hamamatsu C7700 (5 ps resolution) coupled with a CCD camera ORCA II (1344x1024 pixels) cooled down to -60°C.

Left: excitation part , right: detection part.

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Examples :

 Temperature-resolved lifetime evolution for two compounds: (TDMP)PbBr₄ and (BAPP)Pb₂Br₈

Time-resolved PL on [C₆H₁₆N₂]₃[Cu₄Br₆][Cu₂Br₆].
(a) Streak camera images obtained for two temporal windows.
(b) and (c) Decays integrated on red and green rectangles, monoexponential behavior.
(Scientific Reports, 2017, 7, 45537).

 

Temporal behaviour differences for CdSe quantum dots emissions in solution or thin film.
(Applied Physics Letters, 2010, 97, 153111).