Department of Chemical Technology, University of Calcutta, 92 A. P. C. Road, Calcutta-700 009 Manuscript received 20 April 1994. accepted 17 June 1994 Ultrafine CdS and ZnS in AOT-heptane-water microemulsion can be easily synthesised in situ by using an ultrasonic processor as homogeniser. The clusters exhibit 'the quantum size effect'. The average diameter of particles, as manifested in the photoabsorption thresholds of colloidal semiconductors, increases as the water content of reverse

more »

... s and the concentration of Q-state particles increases. The emission behaviour of CdS shows a corresponding red-shift with increasing particle size and it can be effectively quenched by injecting electron/hole scavengers in the inner water pool.