As mentioned in Section 3.1, the p-type and n-type doped poly-SiOx CSPCs with 2-step annealing technique are used as the hole and electron contacts in DST solar cells, respectively. The change in passivation after different fabrication steps for the DST solar cell precursor is shown in Figure 5(b). The increase in passivation after hydrogenation and its decrease after ITO deposition are as expected. However, unlike the SST case, the loss in passivation after TCO deposition is not fully recovered after hydrogen annealing at 400 °C for 1 hour. This is because the DST solar cell precursor has p-type doped CSPC applied to the textured side, which is the limiting factor in terms of passivation and does not recover its passivation even after such a hydrogen annealing. The best DST solar cell gave a certified designated area PCE of 19.44% (Voc = 655 mV, Jsc = 37.85 mA/cm2, FF = 78.42%, metallization faction ~3%, designated area = 3.903 cm2, see Figure 5(d)). Compared to the SST solar cell, despite suffering from poorer surface passivation as witnessed by the lower Voc and FF, the DST cell exhibits higher Jsc. This gain can be ascribed to the textured rear side of the DST solar cell which promotes a more efficient light scattering at the rear side and thus higher absorption in the c-Si bulk. Figure 6(a) shows the EQE of the SST and DST devices. As expected, the EQE of the DST cell outperforms that of the SST cell at wavelengths above 800 nm.