Theoretical description of charge transport in disordered organic semiconductors

Twenty years ago Heinz Bassler published in this journal the seminal review article on charge transport in disordered organic semiconductors [Phys. Status Solidi B 175, 15 (1993)], which has become one of the most popular references in this research field. Thanks to this paper, our understanding of charge transport in disordered organic materials has been essentially improved in the past two decades. New theoretical methods have been developed and new results on various phenomena related to charge transport in disordered organic materials have been obtained. The aim of the current review is to present these new theoretical methods and to highlight the most essential results obtained in their framework. While theoretical consideration in the article by Bassler was based on computer simulations, particular attention in the current review is given to the development of analytical theories. Dependences of charge carrier mobility and diffusivity on temperature, electric field, carrier concentration and on material and sample parameters are discussed in detail. Schematic behaviour of charge carriers within the Gaussian density of states (DOS)