Comprehending ‘Glass Relaxation’ and Why It is Vital for Next-Generation Displays

Next-generation displays will feature enhanced resolution and performance, but getting there will require a shift to smaller individual pixel sizes and a tightening of the tolerance for glass relaxation. Display manufacturer can account for a specific level of relaxation in the glass, referring to the intermolecular rearrangement, if it is known and reproducible. 

 

But fluctuations in such relaxation behaviour tend to introduce uncertainty into the manufacturing procedure, possibly resulting in misalignment of pixels within displays. Such fluctuations are caused by small variations in the thermal history of the glass, and unfortunately no one has ever performed a systematic study of what governs fluctuations in the relaxation behaviour of glass.

 

But now, a scientist duo from Corning Inc, a glass manufacturer, and Qilu University of Technology in China, reports on a novel modelling method to quantify and predict glass relaxation fluctuations. Significantly, their research offers a better comprehension of the physical origins of such fluctuations.

 

“Glass is a thermodynamically unstable substance that continually relaxes toward the supercooled liquid state,” says John Mauro, a senior research manager of glass research at Corning Inc. “This relaxation is a spontaneous procedure that is accelerated during the heat treatment.” Makers of flat-panel displays heat the glass to deposit the slim-film transistors for the display. Glass can relax during the heat treatment process, and this relaxation typically involves a slight shrinkage in the volume of the glass. If unregulated, this shrinkage can result in to misalignment of pixels and a non-functioning display.

 

Quiuju Zheng, an associate lecturer at Qilu University of Technology, and Mauro are believed to be the first to explore the fluctuations in the relaxation behaviour of glass by emphasizing on how much the magnitude of the relaxation usually involves a slight shrinkage in the volume of the glass. If uncontrolled, this shrinkage can result in misalignment of pixels and a non-functioning display.

According to Mauro, the insights gained from this work are “already being put to employ developing our next-generation glass substrates for high-performance display,” he also says. “There are numerous other properties of the glass that we are interested in, and this offers one important component for a bigger set of models that we use to help guide the design and development of novel high-tech glass compositions.”

 

The scientists now look forward to addressing a remaining ‘big gap in building the connection between the physics of glass relaxation and the underlying glass chemistry,” says Mauro. 

 

The science of such glass relaxation effects centre around subtle changes, usually measured in terms of parts per million of liner strain. “Since these effects are so subtle, we still do not comprehend, what is altering in the underlying glass structure to facilitate this relaxation in terms of which elements in the glass are undergoing slight re-arrangements in bond configurations, and why,” Mauro says. “Building this bridge between glass physicists and glass chemistry is the next grand challenge that we should undertake.”