Space-charge-limited hole current in poly(9,9-dioctylfluorene) diodes

作者：Nicolai H T^*; Wetzelaer G A H; Kuik M; Kronemeijer A J; de Boer B; Blom P W M

来源：Applied Physics Letters, 2010, 96(17): 172107.

DOI：10.1063/1.3391668

• hole mobility
• ionisation
• molybdenum compounds
• ohmic contacts
• organic light emitting diodes
• polymers
• space charge
• time of flight spectra

Characterization of the hole transport in blue-emitting polymers as poly(9,9-dioctylfluorene) (PFO) is strongly hindered by their large ionization potential of similar to 6 eV. Using common anodes as poly(3,4-ethylenedioxythiophene)/poly(styrenesulphonic acid) leads to a strongly injection limited current. We demonstrate that molybdenum trioxide forms an Ohmic hole contact on PFO, enabling the observation of a space-charge-limited current(SCLC). This allows a direct determination of the hole mobility PFO of 1.3x10(-9) m(2)/V s at room temperature, in good agreement with previously reported mobility values determined by time-of-flight measurements.

• 出版日期2010-4-26