Observation of room temperature mono-electron phenomena on nanometre-sized CdS particles

A STM study of ultra-small cadmium sulphide particles formed in a bilayer of cadmium arachidate exposed to a hydrogen sulphide atmosphere is reported. Particles of nanometre size were identified as negative features inside the film after the reaction. Voltage-current characteristics of particles of different apparent sizes were measured by means of the microscope probe. The behaviour of the tunnelling current indicates the occurrence of a Coulomb staircase at room temperature and reveals a new phenomenon which shows the appearance of regions with negative resistance.