Substitutional Platinum as an Efficient Nonradiative Recombination Center in Silicon

Platinum (Pt) is widely used for carrier-lifetime control in silicon power devices, yet the microscopic nonradiative recombination mechanism of the substitutional platinum (Pt_Si) dopant remains debated. Using first-principles calculations combined with nonradiative multiphonon theory, we systematically investigate the electronic structures and carrier capture dynamics of Pt_Si. Our results show that both the donor (+/0) and acceptor (0/-) levels of Pt_Si exhibit large capture cross sections for electron and hole carriers, thereby making Pt_Si an effective recombination center. Notably, the calculated capture cross sections are sensitive to the symmetry-equivalent defect configurations with different Jahn-Teller distortions. By properly accounting for two different D_2d configurations of neutral Pt_Si during transitions, our calculated carrier capture cross sections align well with experimental values. This work provides a microscopic picture of the carrier capture processes induced by Pt_Si and emphasizes the importance of symmetry-equivalent configurations in defect-assisted nonradiative recombination.