High performance few-layered h-BN-based MIS blocks by Fowler-Nordheim tunneling for infrared photodetection

Hexagonal Boron Nitride (h-BN) is a promising material for a wide range of applications. Since its discovery, it has been used in nanoelectronic and optoelectronic devices as an optimal substrate for various two-dimensional materials. In addition, h-BN is a natural hyperbolic material in the mid-infrared region, where there are few options for photonic materials. To understand the relationships between structure and properties, it is essential to assess the number of layers in h-BN at the nanoscale. Here, using a combination of simulation and experiment, we systematically studied on the Fowler-Nordheim tunneling effect in few-layer h-BN, and basic physical parameters such as the layer-dependent effective mass are accurately obtained and verified. This work proceeds with a systematic investigation on the design of GaN-based metal/insulator/semiconductor (MIS) blocks with few-layered h-BN as insulating layers. It is found that the structural and material properties such as the number of h-BN layers, the GaN doping concentration, and the work function of contact metals exert dominant influence on the electrical characteristics of these MIS blocks, while the ideal heterogeneous interfaces of the 2D h-BN films mitigate the suffering by non-ideal factors such as interfacial traps and SRH recombination. By comprehensively balancing the mutual constraints of the key factors, this work achieves GaN-based MIS blocks capable of operating under higher voltages, currents, or power conditions compared to their counterparts. This paper aims to provide the fundamental physics of h-BN devices and help develop related h-BN-based infrared optoelectronics.