Keywords: porous silicon, thermally stimulated luminescence, charge carrier traps, tunnelling luminescence, localisation mechanism, Auger process, nanotechnology, oxidised nanosilicon, quantum wires, photoluminescence, thermoluminescence, charge pump
'Charge pump' effect and mechanisms of charge carriers localisation in oxidised nano-Si
A new effect of 'two-stroke charge pump' has been experimentally observed in nano-Si, which is based on the Auger process ejecting charge carriers from a silicon nanocrystalline core into enveloping SiOx layer. The effect is important for understanding the nature of such phenomena as dimensional decrease of quantum efficiency of emission, space separation of charge carriers and peculiarities of their localisation. A new mechanism of charge carrier localisation by 'topological' traps in undulating quantum wires has been considered. The developed models are supported by the results of comprehensive spectral investigations of photoluminescence, thermoluminescence, and tunnelling luminescence.