Understanding the Working Mechanism of Vertical Organic Light Emitting Transistors

Vertical Organic Light Emitting Transistors (VOLETs) are a new technology that integrates vertical organic thin film transistors with the organic light emitting diodes into a single device [1]. Their vertical structure and ability to be processed on flexible substrates will create a new horizon for current display technology [2]. Despite their excellent prospects, there are a lot of unexplored areas of VOLETs, both in theory and experiment. Here, we study the operation of VOLETs experimentally and theoretically. In particular, we show that the injection barrier at the source electrode determines the ON/OFF ratio of the transistors and that a significant barrier is needed to reduce the off-currents of these devices. By a comparison of vertical transistors with different semiconductor materials and different injection barriers, we show that a compromise has to be found between large on-currents, requiring a low contact resistance, and large switching ratios.

References
[1] Lüssem, B., Günther, A., Fischer, A., Kasemann, D., & Leo, K. (2015). Journal of Physics: Condensed Matter, 27(44), 443003.
[2] McCarthy, M. A., Liu, B., Donoghue, E. P., Kravchenko, I., Kim, D. Y., So, F., & Rinzler, A. G. (2011). Science, 332(6029), 570-573.