Favored for their image quality and brightness, OLEDs are commonly used in AR applications for vibrant and clearly visible content under variable lighting conditions and in VR for realistic and bright images. They are also used in military applications for clear visibility of commands and situational indicators in military devices under extreme conditions. However, when operating at high brightness in harsh environments, OLEDs show certain limitations. A common method to increase the brightness of OLEDs while maintaining a long lifespan is the use of multiple stacked OLEDs. This however increases the voltage drop and swing across the OLED stack. To address this, scientists at the Fraunhofer Institute for Photonic Microsystems IPMS (Fraunhofer IPMS) have developed a high-voltage CMOS backplane that enables exceptionally bright OLED-based microdisplays. A 0.62-in OLED microdisplay enabled by Fraunhofer IPMS’s recently developed high-voltage CMOS backplane. Courtesy of Fraunhofer IPMS. “We have developed an innovative pixel cell design that allows for a voltage swing of over 10 volts, enabling the operation of multiple stacked, top-emitting OLED layers,” said Uwe Vogel, head of microdisplays and sensors at Fraunhofer IPMS. “Depending on the number of stacked units, multiples of the maximum emission can be achieved with high current efficiency while maintaining constant current density.” The approach, he said, allows for full color maximum brightness over 10,000 candela per square meter (cd/m2) without compromising lifespan or reliability. Micro-LEDs are often presented as a high brightness alternative to OLEDs, but the technology is not yet mature and suffers from efficiency loss at the high pixel densities required of high-resolution microsdiplays. Micro-LED displays in these applications must be operated with more than 1 A/cm2. In contrast, the current density for OLEDs during long-lifespan operation is typically below 100 mA/cm2. The technology developed by Fraunhofer IPMS allows for greater brightness than previously possible, expanding market opportunities for high brightness OLED microdisplays, enabling users to benefit from their maturity, efficiency, and color representation. Meanwhile, micro-LEDs continue to advance to offer similar benefits. The technology will be presented for the first time at the SID Display Week 2025 from May 13-15.