Monolithic Free-Standing Large-Area Vertical III-N Light-Emitting Diode Arrays by One-Step h-BN-Based Thermomechanical Self-Lift-Off and Transfer

We demonstrate the fabrication of vertical InGaN light-emitting diodes (LEDs) on large-area free-standing membranes, using a mechanical lift-off technique enabled by 2D h-BN. 30 μm-thick electroplated copper deposited on the epilayer (i) gives rigidity to the structure, preventing crack generation, (ii) functions as a back mirror and as a heat sink, and (iii) enables one-step self-lift-off and transfer of LED structures from h-BN/sapphire during a thermal treatment at 100 °C. Free-standing arrays of LEDs on thick membranes were processed and their electro-optical performance was characterized. This approach can provide a solution for the fabrication of low-cost, wafer scale, crack-free, and highly reproducible free-standing arrays of vertical LEDs with up to centimeter-size areas.