Figure 2

Energy level diagrams of the devices with stacked PbS layers under (a) dark and (b) illuminated conditions. Efn and Efp denote the quasi-Fermi levels of electrons and holes, respectively.

Energy level diagrams of the devices with stacked PbS layers under (a) dark and (b) illuminated conditions. Efn and Efp denote the quasi-Fermi levels of electrons and holes, respectively.