3.1 Effect of ICO/Ag back reflector for SCH solar cell
For most reported SCH solar cells with the carrier transport layer on the back side, the metal electrode was usually deposited directly on the carrier transport layer [26,27]. Although the process is relatively simple, the parasitic absorption of the metal electrode often leads to reductions in the quantum efficiency and Jsc. Indium cerium oxide (ICO), recently widely used in the SHJ solar cells as the TCO layer, shows excellent optoelectronic properties such as high mobility, high transmittance, and low free carrier absorption[28,29,30]. Here, besides serving as the top transparent electrode, ICO film is inserted between the MoOx layer and the back Ag electrode in the SCH solar cells as shown in Figure 1 (a). The ICO/Ag combination on the rear of the SCH solar cells was expected to serve as a back reflector.