Integrated Triboelectric Nanogenerator and Photovoltaic Systems Using InP/ZnSe Quantum Dots for Smart Security Applications

In this study, cadmium-free InP/ZnSe core–shell quantum dots (QDs) were synthesized using the hot-injection method, with the measured barrier height of the PN junction being approximately 0.441 eV. The core–shell structure significantly improved the photoluminescence quantum yield (PLQY) compared to that of bare InP QDs, with enhanced optical properties and stability due to effective lattice matching between InP and ZnSe, reducing interfacial defects. These QDs were integrated into a hybrid energy-harvesting device by combining a triboelectric nanogenerator (TENG) and a photovoltaic (PV) thin film. The TENG, based on a PMMA–QDs composite film, achieved a high output power density of 191.13 μW/cm2 under 3 Hz mechanical excitation, while the PV device exhibited a light-switching ratio as high as 73.5, demonstrating excellent photoresponsivity. Additionally, a smart security lock system was developed, utilizing the TENG’s personal information recognition capability to authorize access based on a friction-generated electrical signal, with an integrated alarm system to detect unauthorized code acquisition via light-excited fluorescent substances. This dual-response energy system offers a promising approach for efficient and reliable energy harvesting with potential applications in sustainable electronics and self-powered IoT devices.