Quantum Dot-Based Flexible Photodetectors: A Review

Photodetectors (PDs) are a crucial area of research in photonic devices, essential for light-sensing technology across various applications. Recently, the development of flexible photodetectors (FPDs) has represented a transformative advancement, offering remarkable properties, such as the ability to bend, twist, and conform to different surfaces. This flexibility opens the door to a plethora of applications including wearable electronics, health monitoring devices, smart clothing, and artificial skin. Researchers are actively exploring ways to enhance FPD performance by improving performance parameters, such as responsivity, detectivity, sensitivity, on–off current ratio, response time, dark current, and stability. Quantum dots (QDs) have emerged as powerful tools in advancing PD technology. Due to the quantum confinement effect, QDs offer tunable bandgaps, enabling broadband response from ultraviolet (UV) to infrared (IR) regions. The integration of QDs into FPDs leverages these properties, leading to significant improvements in device performance. This Perspective provides a comprehensive overview of QD-based FPDs, discussing various QD materials and flexible substrates utilized in these devices. It also highlights cost-effective solution-processed approaches for QD synthesis and the role of ligand exchange methods in optimizing device performance. The review delves into the diverse applications of QD-based FPDs and addresses the challenges and future research directions needed to further advance this promising field.