Figure 1.

Symbols indicate numerical calculations for the open-circuit voltages V_OC (upper panel) and the fill factors FF (lower panel) for CdS/CdTe solar cells under solar illumination at 300 K. The horizontal axis is the ratio of electron carrier mobility μ_e and the square of grain size θ as given in the key. Note the linear dependence of the V_OC upon the μ_e/θ² ratio as guided by the solid gray line. The solid line represents the analytical solution given by eq 2b with uniform photogeneration G = 6.3 × 10²⁰ cm^–3 s^–1. The dashed lines are guides for the eye and indicate the open-circuit voltage V_OC^champ and the fill factor FF^champ for the champion CdTe thin-film solar cell at 298 K.¹³