On the minimum thickness of doped Electron/Hole Transport Layers in organic semiconductor devices

D. Oussalah (1) , R. Clerc (2) , J. Baylet (1) , R. Paquet (1) , C. Sésé (1) , C. Laugier (1) , B. Racine (1) , J. Vaillant (1)

1 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
2 LHC - Laboratoire Hubert Curien

Doped hole (resp. electron) transport layers HTL (resp. ETL) are commonly used in evaporated organic devices to achieve high work function hole contact (resp. low work function electron contact) in OLED to inject large current, in solar cell to increase the open circuit voltage, and in photodetector to minimize the dark current. However, the optimisation of the HTL thickness results from a delicate trade off. Indeed, on one hand, to minimize the impact of HTL on light propagation and series resistance effects, it is commonly admitted that HTL must be kept as thin as possible. On the other hand, as discussed in this paper, due to field effect, a minimum thickness is needed to reach an efficient work function by doping. Combining modelling, simulation and experiments (performed on a template P_only TiN/STTB:F$_4$TCNQ/ZnPc:C$_{60}$/Ag device), the aim of this paper is to identify the mechanisms that determine the value of this minimum thickness.

Domains: Physics [physics]

D. Oussalah, R. Clerc, J. Baylet, R. Paquet, C. Sésé, et al.. On the minimum thickness of doped Electron/Hole Transport Layers in organic semiconductor devices. Journal of Applied Physics, 2021, 130 (12), pp.125502. ⟨10.1063/5.0060429⟩. ⟨hal-03358906⟩