Author/Authors :
A.F. Savvateev، نويسنده , , V.N. and Tarabia، نويسنده , , M. and Chayet، نويسنده , , H. and Farragi، نويسنده , , E.-Z. and Cohen، نويسنده , , G.-B. and Kirstein، نويسنده , , S. and Davidov، نويسنده , , D. and Avny، نويسنده , , A.Y. and Neumann، نويسنده , , R.، نويسنده ,
Abstract :
We have studied the current versus voltage (I–V) and the luminescence versus voltage (EL-V) characteristics in PPV-based LED devices for different film thickness, d. For voltages below the EL threshold voltage, the I–V curves exhibit a linear regime (I~V) at low voltages and quadratic (I~V2) regime for higher voltages. The later is attributed to the space charge limited current mechanism assuming a single shallow trap level. The fit of the model to the experimental results is very good with a single fitting parameter, namely, the effective mobility. The extracted mobilities are compared to those measured independently by time-of-flight (TOF) photoconductivity. The SCLC model gives a reasonable explanation for the voltage threshold in EL
