Perovskite LED Paves Path for Perovskite Lasers

Belgian research lab Imec has announced a major breakthrough in LED technology. The lab claims to have created a metal halide perovskite LED stack that emits 1,000 times more light than state-of-the-art OLEDs. This achievement is a significant milestone towards the development of a perovskite injection laser, with potential applications in image projection, environmental sensing, and medical diagnostics.

The research team at Imec, working within the EU Horizon 2020 funded project called Ultra-Lux, has developed perovskite-based LEDs, which they refer to as "PeLEDs." These PeLEDs have a unique architecture consisting of transport layers, transparent electrodes, and perovskite as the active material. This architecture allows the PeLEDs to operate at current densities that support the stimulated emission of light, reaching levels tens of thousands of times higher than conventional OLEDs.

Imec's principal investigator, Professor Paul Heremans, explains, "This architecture of transport layers, transparent electrodes, and perovskite as the active material can operate at 3kA/cm2, tens of thousands of times higher than conventional OLEDs can." The team achieved this breakthrough by combining electrical pumping with conventional optical pumping, resulting in an electrical injection that contributes 13% to the total amount of stimulated emission. This brings them closer to achieving a thin film injection laser.

The proof-of-concept device developed by Imec was operated at 77K and exhibited amplified stimulated emission above 9.1μJ/cm2 when stimulated with 2.3ns optical pulses. The team also achieved a current density of 3kA/cm2 using sub-microsecond electrical excitation with irradiance values above 40W/cm2. Co-pumping optical pulses synchronized with the leading edge of an electrical pulse further reduced the amplified stimulated emission threshold, demonstrating the contribution of electrically injected carriers to optical gain.

In their paper published in Nature Photonics, Imec describes how they probed the PeLED with 1μs long optical excitation and observed continuous-wave amplified stimulated emission at a threshold of 3.8kW/cm2. Additionally, electrical pulses generated electroluminescence close to half the irradiance produced by continuous-wave optical pumping at the amplified stimulated emission threshold.

This breakthrough in perovskite LED technology opens up new possibilities for the development of highly efficient and high-intensity light sources. Imec's research brings us one step closer to the realization of perovskite injection lasers, which could revolutionize various industries, including image projection, environmental sensing, and medical diagnostics.