Charge dynamics of muonium centers in Si revealed by photoinduced muon spin relaxation

Muonium dynamics in crystalline Si has been studied in both p-type and n-type samples using the muon spin-relaxation technique combined with photoexcitation. Controlling the excess carrier density in this way has revealed the dynamics of charge-exchange cycles and transfer processes involving MuBC0/+ and MuT^-/0. In particular, photoexcitation has provided access to processes involving hole capture not attained by conventional experimental techniques. As a consequence, strong evidence was found for the delayed formation of electrically inactive muonium states in both types of Si, suggesting a process of diffusion-limited direct interaction of muonium with dopant impurities (i.e., muonium passivation).