2D/3D Hybrid of MoS2/GaN for a High-Performance Broadband Photodetector

Narrow spectral sensitivity in materials is one of the crucial challenges to develop high-performance broadband photodetectors. Here, we design a heterostructure of two-dimensional molybdenum disulfide (MoS2) and epitaxial gallium nitride (GaN) films to create an enhanced spectral absorption profile. This combination utilizes complementary optical absorption of MoS2 (visible) and GaN (UV) driven by type II band alignment at their interface to showcase highly sensitive photodetectors spanning across the UV-NIR regime. Concurrently, the heterostructure exhibits significantly enhanced responsivity (order of 104 A/W) and external quantum efficiency that are 500% higher than the bare GaN photodetectors. Given the available scalable synthesis approaches that have now been designed by the research community for both constituent materials, the demonstration of this heterostructure as a broadband photodetector with high figures-of-merit opens opportunities in designing efficient optoelectronic junctions and imaging applications.