Beneficial effect of tributylphosphine to the photoluminescence of PbSe and PbSe/CdSe nanocrystals

A small quantity of tributylphosphine was employed to improve the surface state of fresh and oxidized PbSe nanocrystals after the formation of nanocrystals. Experimental results showed that the photoluminescence intensity increased in both situations. However, an excessive amount of tributylphosphine exhibited negative effects of decreasing photoluminescence and particle aggregation. A suitable amount of tributylphosphine added before the synthesis of a CdSe shell on PbSe core (PbSe/CdSe) also exhibited a photoluminescence intensity increase for these core/shell nanocrystals.