We have observed quenching in luminescence intensity for our prepared thin films. How to calculate Internal photon conversion efficiency (IPEC)? Does quantum yield is necessary to measure IPEC?
Can you give precise definition of required quantity. There is the internal quantum efficiency and the external quantum efficiency and the photo conversion efficiency of a solar cell which is the maximum output electrical power to the incident solar radiation power.
Would you mean the internally produced photon flux power to received internal photo flux power. If so one can assume that received photo flux at specific wavelength lambda Fi(lambda), in phoitons/cm^2/s in the wavelength interval d lambda, the every photon will generate an electron hole pair if it is absorbed and we speak only from those absorbed in the internal efficiency. Then the number of generated electron hole pairs will be equal also to F(lambda). Not all these e-h pairs will generate photons only the radiative recombination will result in generating photons. Because of the balance between the generation and the recombination for steady condition, Then g= r= dn( 1/Trad+1/Tnonrad) where dn is the excess electrons or holes due to generation , Trad is the radiative lifetime and Tnonrad is the nonradiatove lifetime. But F= g W where W is the thickness of the film. Then Fi= w dn( 1/Trad+1/Tnonrad),
On the other hand the emanating flux Fo= the radiative rate recombination= dn w/Trad,
Now we can get the spectral internal efficiency ETA as i defined it earlier:
ETA = w dn Trad Tnonrad/ Trad w dn( Trad +Tnonrad)= Tnonrad/( Trad +Tnonrad)
The luminescence Spectra reflects only the radaitive recombination photon flux
if is assumed that it will be totally transmitted outside the material. otherwise one has to multiply Fo by the light transmission efficiency ETAo from the inside to the outside of the film.
In order to get Fi one has to to multiply the external incident photon flux Fe by the input transmission efficiency ETA ti
In summary in order to determine the internal efficiency= (Foe/ ETAto)/ Fe ETAti = Fo/Fi.
This is a complete solution to the problem if you intend my definition.
Best wishes
Zekry
Dear
Thank you for your Kind response.In precise, help us to determine the quantum yield from the luminescence spectra. Quantum yield stands as the ratio of number of photons emitted to the number of photons absorbed. can you help us in this regard.
Dear Isaac,
If you read again my first comment to you, you will find that i gave you a complete road map to determine the quantum yield from the photo response. As i said before you need to determine the reflectance in both directions from outside to the inside of the material and vice verse. The reflectance roh= magnitude square of the reflection coefficient. The reflection coefficient can be calculated given the dielectric constant of the material.
You can assume that the absorbed flux= Fi= PHIi(1- roh), PHIi is the global incident photon flux at a given wavelength.
My two comments complement each other to solve the problem.
Best wishes
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