Interface Engineering in Van der Waals Heterostructures: Enhancing Photodetector Efficiency through Structural and Functional Modifications

2D materials and their van der Waals (vdWs) heterostructures have shown great potential for developing promising applications in optoelectronics, especially for photodetector devices. However, to fully harness their capabilities, precise control over the interfaces between these 2D materials in vdWs heterostructures is pivotal. Interface engineering in vdWs heterostructures has emerged as a key approach in material science as it enables the fine-tuning of the interlayer interactions, their band alignments, and it can control the charge transfer dynamics, ultimately enhancing the photodetector device performance. This review first highlights advanced figures of merit for evaluating photodetector performance and then provides an overview of the fundamentals of vdWs heterostructures, with a focus on their optoelectronic properties. The recent advancements in interface engineering, including surface passivation, defect engineering, and contact engineering, all of which contribute to improving the optical parameters in the photodetector device applications, are provided. New functionalities such as polarization detection and multi-spectral imaging, which open up exciting possibilities in the domain of optoelectronics, are discussed. Lastly, we provide conclusions and future research directions, highlighting the integration of machine learning techniques for optimizing photodetection technology. Despite challenges related to interface quality, scalability, and long-term stability, interface engineering remains a crucial strategy for advancing photodetector performance, enabling innovations and breakthroughs in optoelectronics.