Development of Novel Material with Reversible Photochromism Characteristics, Paving the way for Next Generation Ultrahigh-Density Memories and Displays
Inorganic Photochromic materials has been considered for quite sometimes as an ideal candidate in manufacturing the next generation high-density memories as well as displays, due to their responsiveness to visible light for manufacture high capacity memories by using semiconductor laser or LED as its light source. But most inorganic materials do not exhibit photochromic response to visible light, plus they have a low durability, or even worse they show a slow color change and poor color reversibility (i.e. failed to decolorize after being irradiated several times.). Furthermore, the color of most of these materials was blue. In repose to overcome these inherent difficulties, group of researchers at AIST in Japan has developed a composite metal oxide materials that has a stable and reversible phtochromism when it is irradiated alternately with blue and green monochromatic lights.
This new novel material was prepared by adding metallic elements to barium-magnesium silicate (BaMgSiO4) under reductive atmosphere. The new material’s color density can be controlled by changing the wavelength of irradiated light, for example the material turns into light pink when they are irradiated with laser light of 405nm in wavelength (blue) and turns into deep colored pink when it is irradiated with ultraviolet light of 365 nm in wavelength (green). These color changes are seen to be reversible. The researchers have noticed that the changes in the color of the material when irradiated with light of different wavelengths remain unchanged even after the materials are repeatedly irradiated more than ten times, showing its excellent durability, making it ideal in such applications in ultrahigh-density optical memories, rewritable paper as well as display.