Micro-/Nanostructure-Stabilized Liquid-Crystalline Blue-Phase

Abstract

Currently, the remaining grand challenge liquid crystal displays (LCD's) face in the market is response time (a few milliseconds), which is ∼ 100 times slower than that of OLEDs (∼ 0.1 ms). To achieve the goal of sub-millisecond response time and suppressing the colour breakup issue, blue phase liquid crystal (BPLC) is emerging as a strong candidate. The blue phase is stable in a narrow temperature range and consists of individual liquid crystal molecules arranged into double twisted cylinders. However, the strong wavelength dependent scattering of circularly polarised light dependent on lattice constant and crystal orientation leads to striking visual colour effects which hint at future display applications. To improve temperature stability, cross-linked polymer networks have been used to stabilize the BPLC lattice structure and extend the blue phase temperature range to more than 95°C including room temperature. However, this approach leads to randomly oriented blue phase (BP) structures with poor optical transmittance, contrast and high operating voltage (>100 V) [1].