Large Scale Heterointegration of 2D Hexagonal Boron Nitride and GaN-based Materials for Future Opto-electronic Devices

Hexagonal boron nitride (h-BN) is a futuristic wide bandgap 2D nitride semiconductor material. Wafer-scale growth of high quality two dimensional (2D) materials such as h-BN by MOVPE with possible hetero-integration with existing III-nitrides and other conventional device structures have recently attracted lots of interest [1, 2]. Especially, heterointegration of III-nitrides with h-BN has several advantages, one of them is h-BN growth is compatibible with III-nitride MOVPE growth. It can be grown in the same MOVPE reactor as other IIInitrides, leading to facile integration avoiding contamination and reproduciblity issues. Here we report, exploration of MOVPE van der Waals eptaxial growth of h-BN and successful demonstration of its integration with other III-nitride devices. These material growth by MOVPE has been successfully scaled up to 6” diameter [3]. Further, we present the characteristics of the light emitting diodes grown on h-BN/sapphire which can be lifted off from the sapphire susbtrates, preserving the phyical properties and transfered to any arbitrary templates. Controllable growth of this 2D materials on dielectric patterned substrates leading to selective area growth of III-nitride based device arrays has been employed for realizing transferrable micro-LEDs with smooth side walls [4]. In addition, these BN in bulk form can be can be employed effectively as a hole injection layer in active UV-LED structures. We demonstrate electrically stimulated emission from the p-hBN/AlGaN MQWs/n-AlGaN structure around 290 nm. These growth experiments on scaling up and heterointegration gives a very important insight on the possible commercialization of use of 2D materials integration in novel device structures, especially h-BN which will be discussed as a path forward to solve the critical issues in free standing/indivually addressable, thin flexible LEDs and other novel device structures.<br/><br/>References:<br/>[1] J. Shin et. al., Nature, 2023, 614, 81-87.<br/>[2] Han et al., Science, 2024, 384, 312–317.<br/>[3] P.Vuong, T. Moudakir, R. Gujrati, et. al., Adv. Mater. Technol., 2023, 2300600, 1–7.<br/>[4] R. Gujrati, A. Srivastava, P. Vuong, et. al., Adv. Mater. Technol., 2023, 2300147, 1–10.