Comparison of three IBSCs in terms of photo-filling, capture cross section of carriers, the concentration of IB states and overlapping of absorption coefficients in the wide range of band gaps including GaAs.

Intermediate-band solar cells, IBSCs, with single IB provide better utilization of the solar spectrum than single junction solar cells. In this study, Model − B IBSC was proposed, investigated and compared with previously used two models named here as Model − A and Model − C respectively. Detailed Balance Model was applied to satisfy Current Balance Equations with the optimum photo filling of IB states in Model − B. Optimum design parameters were obtained using 104 cm−1 of band-to-band absorption coefficient, α , in the wide range of band gap materials, overlapping absorption, photo filling, f , of IB states, capture cross-section ratio of carriers, concentration of IB states, and IB layer thickness, w , under 1–46,000 sun concentration, X. Maximum limiting efficiency value of 63.2% has been obtained with 1.95 eV of band gap, for f α w ≥ 5 and 46,000 X , under non-overlapping absorption. The peak efficiency of Model − B was 16% over the Model − A and 8% over the Model − C , for equal capture cross sections under large overlapping. The peak efficiency of Model − B was 35% over Model − A , at large non-equal capture cross-sections and large overlapping. Results predicted that the materials in the wide range of band gaps could be good candidates for fabricating IBSCs using Model − B with an efficiency of 50% or above at lower sun concentration, 10,000 X , even under large overlapping. [ABSTRACT FROM AUTHOR]