Overcoming the Challenges Associated with the InN/InGaN Heterostructure via a Nanostructuring Approach for Broad Band Photodetection

One-dimensional nanostructures such as nanorods (NRs) and nanowires have garnered great interest, making them prospective candidates for the development of next-generation nanostructured devices. Herein, a self-powered, broad band, and ultrafast photodetector based on the n+-InN NRs/n-InGaN epilayer heterojunction has been demonstrated. The NRs and epilayer were grown on the AlN/n-Si(111) template by using plasma-assisted molecular beam epitaxy. The device exhibits an outstanding self-powered photodetection in the UV, visible, and infrared (IR) (300–1200 and 1550 nm) ranges with a maximum responsivity of 243.7 mA/W (675 nm). The response and recovery times have been estimated to be 358 and 103 μs, respectively. The maximum responsivity observed at 675 nm is believed to be due to the intermediate energy levels present in the forbidden gap of InGaN due to the nitrogen vacancies. The observed sublinear dependency of the photocurrent on the incident power density has been ascribed to the presence of interfacial inhomogeneities and defects. We believe that our findings would help in fabrication of high-quality optoelectronic devices as well as provide a deeper understanding of the transport properties of such NR-based heterojunctions.