Figure 4
The Voc behavior of the perovskite solar cells is represented in the energy level diagrams by employing (a) narrow or (b) wide band gaps (Eg) perovskite absorber, and (c) different HTMs, such as spiro-OMeTAD/Au in (a) and (b) or deeper work function (WF) P3HT/MoO3/Au in (c). The conduction band (Ec), valence band (Ev), Fermi level of electrons (EFn) and holes (EFp) were indicated. The MoO3 layer creates a dipole (Δ) at the interface, reducing the vacuum level energy (Evac). The Au performs as the electron blocking layer.
