A figure of merit to evaluate transparent conductor oxides for solar cells using photonic flux density

• A figure of merit is presented for the evaluation of TCO used in solar cells.
• It is defined as the ratio of photo-current density over TCO sheet resistance.
• It is a tool for a fine comparison of TCO films in solar cell development.

We report an alternative method to evaluate transparent conductor oxides (TCO) from their photonic flux density (PFD(hυ)) to be used in solar cells. From the transmittance spectrum (T(hυ)) in the visible region, we calculate the PFD(hυ) and the solar photon flux-weighted transmittance (TSW) of one specific TCO with potential application in solar cells. The photo-current density (JPH) in mA/cm2 of one specific TCO when exposed to white light is evaluated when PFD(hυ) is integrated over the whole solar electromagnetic spectrum. Finally, we define a figure of merit as JPH over the TCO film sheet resistance to find the best equilibrium between the transmission and its electrical resistance. To carry out this work, a bibliographical search of investigations about development of TCOs was extensively made to evaluate its T(hυ), TSW, PFD(hυ), JPH and the figure of merit that we propose. From our results, we consider that the proposed method is a good tool for a fine comparison of transparent conductive films in solar cell development.