Electron-hole recombination confinement in self-organized AgBr nanocrystals in a crystalline KBr matrix

The phenomenon of spatial confinement of the electron-hole recombination in exchange-coupled donor-acceptor pairs was observed by optically detected magnetic resonance in AgBr nanocrystals formed as a result of the self-organized growth in an ionic KBr crystal matrix. The effect is manifested by the maximum distance between recombining donors and acceptors being restricted to the nanocrystal size and by a change in the $g$ value of shallow electron donor centers. Based on an analysis of the exchange interactions, the distribution of distances in the donor-acceptor pairs is determined and the dimensions of nanocrystals are estimated.