I would like to calculate the theoretical photocurrent density can be obtained for photoanode. can anyone explain how to convert reference solar spectral irradiance at AM 1.5G (W m-2 nm-1) to the solar energy spectrum in terms of number of photons (s-1 m-2 nm-1).?
If you already know the spectral irradiance of each wavelength in W/m2*nm you first need to calculated the number of photons for each wavelength separately: Energy of one photon: W = (h*c)/wavelength. h= Planck constant = 6.626 * 10^-34 J*s, c: speed of light: 299792458 m/s. Then you divide your irradiance at the given wavelength by the energy of the corresponding photon. This results in the numbers of photons for each single wavelength. At the end you just sum up all values in order to get the spectral irradiance in photons/(m2*s).
If you already know the spectral irradiance of each wavelength in W/m2*nm you first need to calculated the number of photons for each wavelength separately: Energy of one photon: W = (h*c)/wavelength. h= Planck constant = 6.626 * 10^-34 J*s, c: speed of light: 299792458 m/s. Then you divide your irradiance at the given wavelength by the energy of the corresponding photon. This results in the numbers of photons for each single wavelength. At the end you just sum up all values in order to get the spectral irradiance in photons/(m2*s).
Dear Ramireddy,
As said by Peter Richter, dividing spectral irradiance with energy of a photon of corresponding wavelength will give you the photon flux distribution. You need to integrate it (or numerically summing up) within the wavelengths of interest and multiply by value of q (1.60217662 × 10-19 coulombs) to get the theoretical maximum possible photocurrent density.
Just to add upon, you might be interested to check the following link where the same has been implemented in a python code.
http://goo.gl/va312U
Scroll down to "2. AM1.5G Photon Flux Vs Wavelength"
Enter the maximum wavelength (in nm) up to which you wish to calculate the theoretical photocurrent density. For example you could enter 1127. 1127 corresponds to the wavelength up to which silicon can absorb (bandgap of silicon 1.1eV).
It will give the graph of Photon flux Vs Wavelength and Maximum Theoretical Current Density.
Hope that helps.
http://goo.gl/va312U
Both above answers are spot-on, but to put it simply: W=Js-1, so to get from Wm-2nm-1 to s-1m-2nm-1 you simply divide by by the photon energy in Joules at each wavelength.
Thank you soo much for your answers, i calculated same as you suggested and got the same. Thank you once again
The AM1.5G spectrum is obtained from the SMARTS model, v2.9.2. You can use it and select outputs in irradiance units, photonic units, or both.
http://www.nrel.gov/rredc/smarts/
hi sir for me the photo flux is 1/t=P/E taking P is the irradiance and E is 1240/λ. simply
There is also open source software available to easily calculate photocurrent densities for single to multi-junction devices. A rather straightforward Python implementation can be found here:
https://codeberg.org/photon/YaSoFo/
or
DOI:10.5281/zenodo.1489158
You can use this origin file, Table contains the Original AM 1.5 G spectral irradiance data from the NREL website.
Used to determine the Ideal short-circuit current density as a function of bandgap.
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