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Fluorescence Lifetime Measurement using Time Correlated Single Photon Counting

Akhtar, Mohammad Bilal (2010) PHYM01 20101
Atomic Physics
Chemical Physics
Abstract
A time correlated single photon counting (TCSPC) setup is built to measure the fluorescence decay of samples, such as solar cell materials. TCSPC is a sensitive technique for measuring fluorescence decays on nanosecond time scale and longer. The principle of TCSPC is based on the precise registration of the arrival time of fluorescence photons from a sample. A fluorescence decay curve is constructed from the TCSPC measurement, this curve is used to extract the fluorescence lifetime. The
setup is novel with respect to the conventional method of collecting a fluorescence signal. It is a simplified setup as there is no need of complex geometry of optics to focus the excitation beam or to image the fluorescence on to the detector. Instead,... (More)
A time correlated single photon counting (TCSPC) setup is built to measure the fluorescence decay of samples, such as solar cell materials. TCSPC is a sensitive technique for measuring fluorescence decays on nanosecond time scale and longer. The principle of TCSPC is based on the precise registration of the arrival time of fluorescence photons from a sample. A fluorescence decay curve is constructed from the TCSPC measurement, this curve is used to extract the fluorescence lifetime. The
setup is novel with respect to the conventional method of collecting a fluorescence signal. It is a simplified setup as there is no need of complex geometry of optics to focus the excitation beam or to image the fluorescence on to the detector. Instead, the excitation beam is unfocused and the sample is placed as close to the detector as possible. This approach allows for the usage of low excitation density of photons.
The low level of light that this setup could detect made it very sensitive for measuring samples with low emission. The setup is characterised with two different samples: Coumarin-152 (7-N,N-dimethylamino-4-trifluoromethyl-1,2-benzopyrone) and APFO3 (poly[2,7-(9,9-dioctylfluorene)-alt-5,5-(4,7′-di-2-thienyl-2′,1′,3-
benzothiadiazole)]). Coumarin-152 is a commercial laser dye and APFO3 is a polymer solar cell material. These measurements reveal that the single and non exponential curves could be obtained using this setup. The verification of the setup is further carried out by classifying different errors that can influence the measurements. (Less)
Abstract
Popular Science Abstract

This thesis is about the construction and demonstration of time correlated single photon counting (TSCPC) setup. The technique is essentially digital and is based on detection and counting of single photon, recognizing quantum nature of light. The time is measured between excitation pulse and detected photons and is stored in histogram with x-axis corresponding to time interval. The sample is excited repeatedly and resulting histogram of intensity versus time called as fluorescence decay curve.

Generally speaking, fluorescence or emission spectroscopy is one of the fundamental spectroscopic techniques. This is the study of fluorescence phenomenon which is the emission of photons from singlet excited state.... (More)
Popular Science Abstract

This thesis is about the construction and demonstration of time correlated single photon counting (TSCPC) setup. The technique is essentially digital and is based on detection and counting of single photon, recognizing quantum nature of light. The time is measured between excitation pulse and detected photons and is stored in histogram with x-axis corresponding to time interval. The sample is excited repeatedly and resulting histogram of intensity versus time called as fluorescence decay curve.

Generally speaking, fluorescence or emission spectroscopy is one of the fundamental spectroscopic techniques. This is the study of fluorescence phenomenon which is the emission of photons from singlet excited state. The emission is red shifted relative to absorption maxima due to loss of energy as heat during relaxation process. In the time resolved fluorescence decay experiment, the sample is excited with pulse of laser
light, it starts with high intensity and then decays, rapidly. Later on from appropriate fitted functions, type of decay, lifetime and amplitudes are calculated. In case of photon counting, the measured data is in form of discrete time function. But still the fitted functions provide the same information. Then question arises about additional
advantage of our TCSPC technique over other life time measurements. The additional benefits come from simplicity of integrated setup i.e. lack of focussing lenses and very low excitation density is required.

The setup has been characterized by measuring the fluorescence decay from organic dye and polymer solar cell material. The data has been fitted with exponential functions and fluorescence life times are calculated with good accuracy. Other than life time measurements, the technique is being successfully used for single molecule detection, TCSPC imaging, and fluorescence correlation spectroscopy in combination
with fluorescence microscopy etc. (Less)
Please use this url to cite or link to this publication:
author
Akhtar, Mohammad Bilal
supervisor
organization
course
PHYM01 20101
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
4075050
date added to LUP
2013-10-02 11:35:54
date last changed
2015-12-14 13:30:19
@misc{4075050,
  abstract     = {Popular Science Abstract

This thesis is about the construction and demonstration of time correlated single photon counting (TSCPC) setup. The technique is essentially digital and is based on detection and counting of single photon, recognizing quantum nature of light. The time is measured between excitation pulse and detected photons and is stored in histogram with x-axis corresponding to time interval. The sample is excited repeatedly and resulting histogram of intensity versus time called as fluorescence decay curve.

Generally speaking, fluorescence or emission spectroscopy is one of the fundamental spectroscopic techniques. This is the study of fluorescence phenomenon which is the emission of photons from singlet excited state. The emission is red shifted relative to absorption maxima due to loss of energy as heat during relaxation process. In the time resolved fluorescence decay experiment, the sample is excited with pulse of laser
light, it starts with high intensity and then decays, rapidly. Later on from appropriate fitted functions, type of decay, lifetime and amplitudes are calculated. In case of photon counting, the measured data is in form of discrete time function. But still the fitted functions provide the same information. Then question arises about additional
advantage of our TCSPC technique over other life time measurements. The additional benefits come from simplicity of integrated setup i.e. lack of focussing lenses and very low excitation density is required.

The setup has been characterized by measuring the fluorescence decay from organic dye and polymer solar cell material. The data has been fitted with exponential functions and fluorescence life times are calculated with good accuracy. Other than life time measurements, the technique is being successfully used for single molecule detection, TCSPC imaging, and fluorescence correlation spectroscopy in combination
with fluorescence microscopy etc.},
  author       = {Akhtar, Mohammad Bilal},
  language     = {eng},
  note         = {Student Paper},
  title        = {Fluorescence Lifetime Measurement using Time Correlated Single Photon Counting},
  year         = {2010},
}