Highly sensitive isopropanol sensor based on Y-doped CdS semiconductor material: Rapid response and recovery mechanism

This study reports, for the first time, the synthesis of yttrium-doped cadmium sulfide (Y-doped CdS) nanomaterials via a one-step hydrothermal method and the fabrication of a high-performance gas sensor for isopropanol detection. At an optimal operating temperature of 162.5 ℃, the sensor exhibited a remarkable response of 400–100 ppm isopropanol, which is approximately five times higher than that of the undoped CdS sensor. Additionally, the device demonstrated ultrafast response/recovery kinetics (8 s/2 s), excellent selectivity, and robust long-term stability. Structural and compositional characterizations indicate that Y-doping induces lattice distortion in the CdS matrix, effectively suppressing grain growth. Furthermore, electron paramagnetic resonance (EPR) analysis revealed that Y 3 + doping significantly increases the concentration of sulfur vacancies. These structural modifications, combined with defect engineering, collectively enhance the gas sensing performance, offering a novel strategy for the rational design of high-efficiency isopropanol sensors.