کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1264334 | 1496841 | 2015 | 9 صفحه PDF | دانلود رایگان |
• We present an analytical model for the space charge limited current in a thin film.
• We derive the two-dimensional version of the one-dimensional Mott–Gurney equation.
• We derive the current for an in-plane photoconductor with non-injecting contacts.
• We analyze the effects of carrier trapping on two-dimensional space charge limited currents.
• We validate the model on an in-plane organic heterojunction photoconductor.
We extend the one-dimensional space-charge limited current theory to a two-dimensional geometry where current flows in a thin layer between two coplanar semi-infinite electrodes. It is shown that the surface charge density in the gap between the electrodes is the finite Hilbert transform of the in-plane component of the electric field. This enables us to derive analytical expressions for the field and charge density for single carrier injection and for photo-carrier extraction by solving a non-linear integral equation for the field. The analytical expressions have been verified by numerical calculations. For the in-plane geometry, the one-dimensional Mott–Gurney equation J=98μ∊V2L3 is replaced by a similar K=2πμ∊V2L2 equation. For extraction of photo-generated carriers the one-dimensional J∼g3/4V1/2J∼g3/4V1/2 dependence is replaced by a K∼g2/3V2/3K∼g2/3V2/3 dependence, where g is the generation rate of photo-carriers. We also extend these results to take into account trapping. We show experimental evidence obtained with an organic photoconductor confirming the predicted voltage, width and generation dependencies.
Figure optionsDownload as PowerPoint slide
Journal: Organic Electronics - Volume 16, January 2015, Pages 212–220