Specialized Korea-based LED developer Lumens announced that it has developed a Monolithic RGB epitaxial wafers for micro-LED display production. The new technology stacks the three color LEDs on on top of the other on the wafer.
A comparison between Lumen's stacked RGB transfer process (bottom) and the standard process (top)
A stacked microLED architecture improves the performance, while also making the transfer process more productive. The company says that its design will offer a dramatic reduction in the production costs - especially the transfer process, which is reduced to a third (in terms of number of transfer steps), while also doing all the process from a single wafer.
To develop the technology, the company developed an InGaN red material, the same material based as the red and green LEDs, which makes it easier to stack on the same wafer. The stacked wafers can be used in all microLED display types - from AR microdisplays to large TV panels.