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 2 d 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.