Organic Semiconductor Junctions

Résumé du livre

Three phases of work are discussed: (1) Screening of a large number of organic systems relative to conductivity and carrier type. Selection criteria were low resistivity (less than 10,000 ohm-cm) and amenability to changing of majority carrier type by additive control ('doping'); (2) Detailed study of additive effects on selected organic semiconductor hosts; (3) Formation of organic p-n junctions - the final objective of this work. The screening phase led to selection of charge transfer complex systems as principal materials of study in phases (2) and (3). Specifically, tetrathiothetracene-orthochloranil, perylene-bromine, magnesium-phthalocyanine and tetracyanoquinodimethane salt systems were studied with various metal and organic additives as 'dopants.' Limited studies were also performed with polymers. Materials with resistivities as low as 0.1 ohm-cm were prepared. Additive control produced large variations of n- and p-type characteristics in a single host system. Results of the second phase of the work led to successful preparation of p-n junction diodes by thermal diffusion of additives. Rectification ratios of up to 200 were achieved. (Author).