HALL EFFECT AND THE OPTICAL ENERGY GAP OF PBS THIN FILMS

Abstract

The carrier concentration (NH) and optical energy gap ( Eg opt ) of PbS thin films prepared by thermal evaporation have been measured. At room temperature and thickness ( 2500 Aº ) , Hall carrier concentration NH was to be found ( 2.9 x 1010) cm-3 , when increases the thickness to ( 3500 Aº ) , NH becomes (1.33x10 12 ) cm-3 and the Hall mobility decreases from 6.73x104cm2.V-1.S-1 to 694cm2. V-1.S-1 . Egopt for indirect transitions were ( 0.45) eV , but for direct transitions (0.57) eV, i.e when the thickness increases the Hall mobility (μH) decreases but the carrier concentration (NH) increases , and the Hall coefficient (RH) decreases .