Enhanced Performance of Giant Power Exponent Superlinear Photodetectors Based on ZnS/MgS Core–Shell Quantum Dots

ABSTRACT In the realm of optoelectronic devices, achieving superlinear performance in photodetectors is crucial for advancing applications in UV detection, optical communication, and sensing technologies. Traditional challenges arise under high light intensities, where increased carrier concentrations lead to higher recombination rates, resulting in sublinear power dependence that hinders performance under high optical power. Here, we introduce a novel ZnS/MgS core/shell quantum dots‐based photodetector that exemplifies these benefits. The device demonstrates exceptional superlinear behavior with a power dependence exponent of 3.6, while achieving a remarkable photoresponsivity of 15.7 A/W, approximately five orders of magnitude (about 60 000 times) higher than that of uncoated ZnS quantum dots‐based detectors. Additionally, the device achieves a detectivity of 3.83 × 10 10 Jones and an external quantum efficiency of 5334%. The photodetector maintains over 90% of its photocurrent after bending to 180° and undergoing 3000 bending cycles, demonstrating excellent flexibility and durability. The ZnS/MgS core–shell quantum dots‐based photodetector represents a significant advancement in optoelectronic technology. Its combination of superlinear response, high responsivity, and robust design underscores its potential for transforming future applications in these fields.