Wafer‐Scale Manufacturing and Crack‐Free Transferring of GaN‐Based Membranes for Flexible Optoelectronics

Heterogeneously integrated devices have great demand for the freestanding wafer-level wide bandgap semiconductors in their single crystal membrane form. However, the current fabrication strategy is quite costly and low throughput. Here, quasi van der Waals epitaxy (QvdWE) of nearly single crystalline GaN membranes on Si(100) substrate via directly-grown graphene interfacial layers are demonstrated. Through simple chemical etching, wafer-scale III-nitride membranes can be readily realized and transferred onto arbitrary substrates, with minimized damage and wafer-scale peeling capability. The obtained flexible InGaN-based light emitting diode device demonstrates strong blue luminescence due to avoiding the crack during transfer process. Meanwhile, flexible ultraviolet photodetector also shows good stability, delivering high responsivity and specific detectivity of 3.52×10⁴ A/W and 6.21×10¹² Jones, respectively. This work indicates that the QvdWE heteroepitaxy and intact transfer strategies can help the combination of GaN-based devices and Si-based integrated circuits.