Figure 4. Limit in the open-circuit voltage in metal-QD Schottky junction solar cells.

The limit of the V_oc as a function of the bandgap (E_g) of PbS QDs: the thermodynamic limit (dash) of V_oc calculated using limiting J_sc and J₀, respectively (Eq. 9); the upper limit (dot) of V_oc calculated using limiting J_sc and experimentally measured J₀ (Eq. 10); the experimentally measured V_oc (solid) as a function of PbS QD size. The inset shows the limiting J_sc in thermodynamic limit as a function of E_g under AM1.5 G.