Optimization of organic light emitting diode for HAT-CN based nano-structured device by study of injection characteristics at anode/organic interface

Abstract

To increase the current density of the hole only device, 1, 4, 5, 8, 9, 11-hexaazatriphenylene-hexacarbonitrile (HAT-CN) material has been inserted in the device at the indium tin oxide (ITO)/organic interface. Since HAT-CN molecule can withdraw electrons, it can alter electronic properties of the electrodes and hence inserted between the organic/metal interfaces. This paper deals with the optimization of the thickness of organic-metal layers to enhance the efficiency. Also, efforts have been made to increase the current density and reduce the operating voltage of the device. The material 2, 7-bis [N, N-bis (4-methoxy-phenyl) amino]-9, 9-spirobifluorene (Meo-Spiro-TPD) is used to simulate the hole only device because it is a thermally stable hole transport material. Simulated results shows that better current density values can be achieved compared to fabricated one by optimizing the organic metal layer thickness. The best optimized layer thickness of 22 nm for Alq₃, 25 nm for CBP* doped with Ir(ppy)₃, 9 nm for Meo-Spiro TPD and 4 nm for HAT-CN which results in current density of 0.12 A/cm² with a reduction in operating voltage by approximately 2 V.

Keywords

organic light emitting diode (OLED) / 2, 7-bis [N,N-bis (4-methoxy-phenyl) amino]-9 / 9-spirobifluorene (Meo-Spiro-TPD) / indium tin oxide (ITO) / model / higher occupied molecular orbital (HOMO) / lower unoccupied molecular orbital (LUMO)

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Acknowledgements

Authors wish to express their gratitude to Amity University, Noida for supporting this simulation work.

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