Black Phosphorus Quantum Dots for Sensing and Optoelectronic Applications: From Fundamental Properties to Device...

Black phosphorus quantum dots (BPQDs) have recently attracted considerable attention as emerging nanomaterials for next-generation sensing and optoelectronic technologies due to their tunable bandgap, strong light-matter interaction, high carrier mobility, and large surface-to-volume ratio. In this review, we systematically summarize recent advances in BPQD-based sensors and optoelectronic devices, focusing on synthesis strategies, physicochemical properties, and device integration mechanisms that govern their performance. Particular attention is devoted to the roles of BPQDs in electrochemical and optical sensing platforms, where their quantum confinement effects, rich surface chemistry, and efficient charge transfer characteristics enable enhanced sensitivity, selectivity, and signal amplification. In addition, recent developments in optoelectronic applications, especially in organic and perovskite solar cells, are critically discussed, highlighting how BPQDs contribute to improved charge transport, interfacial engineering, and device efficiency. Current limitations associated with environmental instability, large-scale synthesis, and long-term operational reliability are also analyzed. Finally, future research directions are proposed to advance the practical implementation of BPQD-based technologies. To the best of our knowledge, this work represents the first comprehensive review specifically dedicated to BPQD-based sensors and optoelectronic devices.