TRANSIENT CURRENT MEASUREMENTS IN PHTHALOCYANINE, AN ORGANIC SEMICONDUCTOR.
Abstract
Using a transient space charge limited current technique and a crystal counter technique, the drift mobilities in the c* direction of metal free and lead phthalocyanine single crystals were determined. Mobilities in the range 0.05-0.1 sq cm/V-sec. in metal free phthalocyanine and 0.6-4.0 sq cm/V-sec. in lead phthalocyanine were observed for both electrons and holes. Definite values of the mobilities and the temperature dependences of the mobilities could not be found from the cusp in the transient space charge limited current technique because of the characteristics of the crystals that were available; namely, small size, severe trapping, and fast recombination in the photogenerated contact. The mobilities were calculated from the initial currents injected. Traps with a density of 10 to the 14th power cu/cm and an activation energy of 0.36 eV were found in both lead and metal free phthalocyanine crystals. These trap characteristics were determined by thermally stimulated trap emptying measurements. These traps were responsible for the fast and severe trapping of carriers observed in the transient current measurements. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1966
- Accession Number
- AD0478736
Entities
People
- C. R. Westgate
- G. Warfield
Organizations
- Princeton University