Patent ID: 7378151

Claim:
A water-soluble semiconductor nanoparticle consisting of: a core made of one chemical compound; a first layer which contains electron-releasing groups directly arranged on a surface of the core; and a second layer made of an ionic compound which is provided on the first layer in order to stablize the first layer, wherein said electron-releasing groups are of at least one type selected from the group consisting of —OR, —OCH 2 R, —OCOCH 2 R, —NHR, —N(CH 2 R) 2 , —NHCOCH 2 R, —CH 2 R, and —C 6 H 4 R, and R is one selected from the group consisting of hydrogen and substituted or unsubstituted hydrocarbon groups, wherein the ionic compound is of at least one type selected from the group consisting of ammonia, primary amines (R 1 NH 2 ), secondary amines (R 1 Rith 2 NH), tertiary amines (R 1 R 2 R 3 N), quaternary ammonium compounds (R 4 R 5 R 6 R 7 N + ), and R 1 to R 7 are each selected from the group consisting of hydrogen and substituted or unsubstituted hydrocarbon groups, wherein said first layer and said second layer are formed from two separate surface treatments, and wherein said semiconductor nanoparticle has a fluorescent property with increased bandgap fluorescence by decreasing defective fluorescence.