Discotic liquid crystals are mesophases formed from disc-shaped molecules known as “discotic mesogens”. These phases are often referred to as columnar phases . Discotic mesogens are typically composed of an aromatic core surrounded by flexible alkyl chains. The aromatic cores allow the transfer of the stacking direction through the conjugate systems. The charge transfer allows the discotic liquid crystals to be electrically semiconductive along the stacking direction. [1] Applications Have Been focusing on using contention systems in photovoltaic devices, [2] Organic light emitting diodes (OLED), [3]and molecular wires. [4] Discotics have also been suggested for use in film compensation, for LCD displays.
Photovoltaic devices
Discotic liquid crystals have similar potentials to the conduct of polymers for their use in photovoltaic cells , they have the same technical challenges of low conductivity and sensitivity to UV damage as the polymer designs. However, one advantage is the self-healing properties of the discotic mesogens. [5] So far the photovoltaic applications have been limited, using a perylene and hexabenzocoronene mesogens in a single two layer systems has only resulted in ~ 2% power efficiency. [2]
Organic light emitting diodes
So far the study in the form of liquid crystals for light emitting diodes are still in its infancy, but there have been some examples produced; A triphenylene and perylene – mesogen combination can be used to make a red LED. [3] The self-assembly properties make them more desirable for manufacturing purposes when producing commercial electronics, than the currently used small molecule crystals in Sony’s new OLED displays. [6] Also, they have the benefit of self-healing properties, as well as being more likely to be beneficial for longevity OLED products.
References
- Jump up^ Laschat, S .; Baro, A .; Steinke, N .; Giesselmann, F .; Hägele, C .; Scalia, G .; Judele, R .; Kapatsina, E .; Sauer, S .; Schreivogel, A .; Tosoni, M. Angewandte Chemie International Edition 2007, 46, 4832-4887.
- ^ Jump up to:a b Schmidt-Mende, L .; Fechtenkotter, A .; Mullen, K .; Moons, E .; Friend, RH; MacKenzie, JD 2001.
- ^ Jump up to:a b Seguy, I .; Jolinat, P .; Destruel, P .; Farenc, J .; Mamy, R .; Bock, H .; Ip, J .; Nguyen, TP Journal of Applied Physics 2001, 89, 5442-5448.
- Jump up^ Steinhart, M .; Zimmermann, S .; Goring, P .; Schaper, AK; Gosele, U .; Weder, C .; Wendorff, JH Nano Lett. 2005, 5, 429-434.
- Jump up^ Kreouzis, T .; Donovan, KJ; Boden, N .; Bushby, RJ; Lozman, OR; Liu, Q. The Journal ofChemical Physics2001, 114, 1797-1802.
- Jump up^ https://www.engadget.com/2007/01/08/sonys-1-000-000-1-contrast-ratio-27-inch-oled-hdtv/
