Photoelectron spectroscopic study of CdS nanocrystallites

Nanocrystallites of semiconductors, especially those belonging to II-VI and III-V groups, show size-dependent optical and electrical properties. In th is paper we report on x-ray photoemission results of CdS nanocrystallites o f two different sizes and compare these results with bulk CdS. The S 2p and 2s core levels of the nanocrystallites reveal three different types of sul fur, unlike bulk CdS, which shows only one kind of sulfur species. Details of the spectroscopic results provide estimates of the size of the nanocryst allites, while also indicating the origin of the stability of such small cl usters. [S0163-1829(99)03811-4].