Hexagonal Boron Nitride Pattern Embedded In Ain Template Layer For Visible-Blind Ultraviolet Photodetectors

We introduced the use of solution-processed few-layer hexagonal boron nitride (h-BN) stripe patterns embedded in the lateral epitaxial overgrowth (LEO) of AlN grown on sapphire substrates using high temperature metal organic chemical vapor deposition (MOCVD). This straightforward usage of h-BN film contributes to reducing the lattice mismatch and almost entirely terminates the threading dislocations originating from the AlN/sapphire interface, which results in a low pit density and the absence of air-voids in the AlN template. Compared with AlN templates grown on conventional sapphire substrates, the full width at half maximum of the AlN template grown on the h-BN pattern in the (0002) and (10-12) planes decreased from 376 arcsec to 227 arcsec and from 495 arcsec to 398 arcsec, respectively. For device applications, AlGaN-based visible-blind UV photodetectors fabricated using the as-obtained high quality AlN templates show one order of magnitude reduction of the dark leakage current and 50% increase in the responsivity. Our results suggest that the h-BN pattern plays a promising role in the growth of a high quality AlN template, leading to the improvement of performance of AlGaN-based optoelectronic devices. (C) 2017 Optical Society of America