Numerical simulation of tetracene light-emitting transistors: A detailed balance of exciton processes

We assess the possibility to use an ambipolar organic light-emitting transistor structure as gain medium for an electrically pumped laser. Singlet and triplet continuity equations are solved together with Poissons and drift-diffusion equations in two dimensions. The solution allows for a detailed balance between the exciton decay, quenching and generation mechanisms. Simulations of a tetracene light-emitting transistor show that triplets are most dominant in quenching singlets. Singlet-triplet quenching can ultimately prevent pure tetracene crystals or films-when provided with a realistic optical feedback structure, to reach the threshold for stimulated emission. (C) 2004 American Institute of Physics.