Liquid-crystalline blue phase II system comprising a bent-core molecule with a wide stable temperature range

Area of Science:

• Materials Science
• Condensed Matter Physics
• Liquid Crystals

Background:

• Blue phase II (BPII) liquid crystals are known for their unique optical properties.
• Achieving thermodynamically stable BPII with a wide operating temperature range has been a significant challenge.

Purpose of the Study:

• To prepare a thermodynamically stable blue phase II (BPII) liquid crystal.
• To evaluate the electrooptical (EO) performance of BPII in a novel host system.
• To assess the potential of this BPII material for high-speed electrooptical devices.

Main Methods:

• Preparation of a host system comprising a conventional rodlike nematogen and a bent-core molecule.
• Evaluation of BPII stability over a temperature range.
• Measurement of electrooptical performance, including response times and the electrooptical Kerr effect.

Main Results:

• A thermodynamically stable BPII phase was successfully prepared with a stability range exceeding 6 °C.
• The BPII exhibited stable electrooptical performance attributed to the electrooptical Kerr effect.
• The temperature dependence of the Kerr effect aligned with Landau-de Gennes theory predictions.
• Very fast response times, on the sub-millisecond scale, were achieved.

Conclusions:

• The developed BPII material offers a significantly wider temperature stability range compared to conventional systems.
• The stable electrooptical performance and fast response times indicate strong potential for high-speed electrooptical applications.
• This research contributes to the advancement of liquid crystal materials for next-generation display technologies.