Hi,
In the case of a Near-Field Thermophotovoltaic (NFTPV) system, the flux you should use for modeling the TPV cell is indeed the one obtained due to the near-field effect. This is because the near-field radiative heat flux is significantly different from standard solar irradiance both in intensity and spectral composition, and it is this flux that the TPV cell will be converting into electricity.
The near-field effect arises when the TPV cell is placed in close proximity to the thermal emitter (the heat source), at distances that are smaller than the characteristic wavelengths of the thermal radiation. This proximity enhances the radiative heat transfer beyond what is predicted by the classical blackbody radiation laws applicable to far-field scenarios.
As a result, the spectral radiative heat flux that you have obtained for your NFTPV system will have a unique distribution that is tailored to the specific properties of your thermal emitter and the gap distance between the emitter and the TPV cell. The TPV cell's ability to generate photocurrent will therefore be directly related to this near-field flux.
When modeling the photocurrent generation in the TPV cell, you will need to account for the following:
- Spectral Dependence: The cell's efficiency at converting photons of different energies (wavelengths) into electrical current.
- Photon Flux: The number of photons incident on the cell per unit area per unit time at each wavelength, derived from your near-field flux measurements.
- Cell Responsivity: The TPV cell's responsivity, which is its ability to generate current as a function of the wavelength of the incident photons.
By incorporating these factors into your model, you can simulate the photocurrent generation and subsequently calculate the J-V and P-V characteristics of the TPV cell under the influence of the near-field thermal flux.
