Scrutinizing thermally stimulated current transients originating from trapped charges in organic semiconductors: A drift-diffusion study

Thermally stimulated current (TSC) is a widely used technique to assess trap states and extract their density, energy, capture rate using analytical expressions. In many cases, the latter are derived from physical models pertaining inorganic semiconductors stipulating absence of space charge or constant lifetime free carriers. Especially for organic semiconductors, validity these equations can, therefore, be argued. Here, we investigate range this approach by fitting classical synthetic TSC data obtained drift-diffusion simulation representative input parameters semiconductors. We find that equation slow recapture as well initial rise method provide excellent parameter predictions. On other hand, temperature peak one fast retrapping have limited validity. An important merit modeling possibility access local variables such carrier electric field, recombinaton. unravel small fraction traps nearby electrode cannot emptied even at high due diffusion carriers into semiconductor. Additionally, an electrostatic factor relates extracted measured external circuit density. For homogeneously distributed here, precisely two. Finally, extensions model analyzed implementing field dependent mobility model.