Light emission and charge trapping in Er-doped silicon dioxide films containing silicon nanocrystals

摘要

The processes of electro- (EL) and photoluminescence (PL) and charge trapping in Er-implanted SiO_2 containing silicon nanoclusters have been studied. It is shown that in Er-doped SiO_2 with an excess of silicon nanoclusters of 10 at. %, a strong energy transfer from silicon nanoclusters results in a ten-fold increase of the PL peak at 1540 nm from Er luminescent centers, whereas the EL is strongly quenched by the excess silicon nanoclusters. It is further shown that the implantation of Er creates in the oxide positive charge traps with a giant cross section (σ_(h0) > 10~(-13) cm~2). Introducing subsequent silicon nanocrystals in the oxide leads to the formation of negative charge traps of a giant cross section (σ_(e0) > 10~(-13) cm~2). The possible reason for the EL quenching in the Er-doped SiO_2 by silicon nanoclusters is discussed.