Strain Engineered Band Gaps and Electronic Properties in PbPdO(2) and PbPd(0.75)Co(0.25)O(2) Slabs

Electronic structure and corresponding electrical properties of PbPdO(2) and PbPd(0.75)Co(0.25)O(2) ultrathin slabs with (002) preferred orientation were systematically investigated using first-principles calculations. The calculated results revealed the strain induced evidently the changes of band structure and carrier concentration in both slabs. It was also found that PbPdO(2) and PbPd(0.75)Co(0.25)O(2) ultrathin slabs exhibited evident differences in the external strain dependence of the band gap and charge carrier concentration, which was strongly dependent on bond angle and bond length induced by in-plane anisotropy strain. Interestingly, the carrier concentration of the PbPd(0.75)Co(0.25)O(2) slab could increase up to 5–6 orders of magnitude with the help of external strain, which could explain the potential mechanism behind the observed colossal strain-induced electrical behaviors. This work demonstrated that the influence of the doping effect in the case of PbPdO(2) could be a potentially fruitful approach for the development of promising piezoresistive materials.