Monolithic Free-Standing Large-Area Vertical III-N Light-Emitting Diode Arrays by One-Step h-BN-Based Thermomechanical Self-Lift-Off and Transfer
Soufiane Karrakchou, Suresh Sundaram, Rajat Gujrati, Phuong Vuong, Adama Mballo, Hibat E. Adjmi, Vishnu Ottapilakkal, Walid El Huni, Karim Bouzid, G. Patriarche, Ali Ahaitouf, Paul L. Voss, Jean‐Paul Salvestrini, A. Ougazzaden
Abstract
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.