From Table , Schottky parameters (n, rs, and qB) increased with the sintering time. For the printed SBDs, n is larger than 2.5, which is much larger than the value for the vacuum-deposited SBD (n = 1.16). In general, the relatively high n implies the formation of an oxide layer at the M/S interface. The relatively high value of rs also implies the existence of an oxide layer at the interface. However, crosssectional SEM observations with elemental analysis of the Ag/p-Si interface indicate no evidence of the existence of an oxide layer in the experimental resolution (Figure , vide infra). Non-existence of an oxide layer strongly suggests that the removal of the native oxide layer and the joining Ag and p-Si took place in order at the first stage of the sintering process. In the sintering process, removing of capping reagents covering AgNPs occurred around 247 °C (vide supra) followed by the decomposition of the reagents through an oxidation reaction at the same temperature. Thus, this oxidation reaction can involve the removal of the oxide layer on the p-Si surface, and then the bared AgNPs can be attached and joined to the p-Si surface, creating an interface that is free from the oxide layer. Also, in particular, the surface energy effect of the AgNPs should facilitate this joining process. Consequently, joining between Ag and p-Si achieved in sintering process causes the high interfacial strength. Therefore, the increment of n and rs with the sintering time cannot be attributed to the oxide layer. Moreover, the possible explanation should interpret the relatively high qB with the increase of sintering time. From the work function of Ag and the Fermi-level of lightly-doped p-Si, theoretical SBH is predicted to be 0.52 eV for Ag/p-Si, and good agreement with experimental data have been reported. However, in our results, though qB of a vacuum-deposited SBD (0.500 eV) shows good agreement with reported data, a series of qB of printed SBDs are high of 0.069-0.141 eV compared with a vacuum-deposited SBD and showed tendency to increase with sintering time.