ZnO Doping-Induced Performance Boost in Co ₂ TiO ₄ /n-Si Schottky Self-Powered Photodetectors

High Resolution Image Download MS PowerPoint Slide In this study, we employed Co 2 TiO 4 and synthesized ZnO-doped Co 2 TiO 4 nanocomposites, which were utilized as interlayers in silicon-based Schottky photodetectors for optoelectronic characterization. Structural analyses using XRD, SEM, and EDX confirmed successful fabrication. The photodetectors were evaluated across a broad spectral range (351–1600 nm) and under varying light intensities. The incorporation of ZnO nanoparticles significantly enhanced the performance of the Co 2 TiO 4 -ZnO/n-Si device compared to its undoped counterpart. Notably, the responsivity ( R ) improved from 0.35 to 17.39 mA/W at 351 nm and from 1.75 to 23.76 mA/W at 1000 nm. Correspondingly, the specific detectivity increased by nearly an order of magnitude, surpassing 10 10 Jones across much of the spectrum. The noise equivalent power (NEP) decreased drastically from 2.16 × 10 –10 to 1.03 × 10 –11 W·Hz –1/2 at 351 nm and from 4.33 × 10 –11 to 7.53 × 10 –12 W. Hz –1/2 at 1000 nm, indicating enhanced sensitivity. The external quantum efficiency (EQE) also improved from 0.13 to 6.43% at 351 nm, with sustained enhancement in the UV–vis-NIR regions. Under 20 mW/cm 2 illumination, the Co 2 TiO 4 -ZnO/n-Si device exhibited a responsivity of 85.99 mA/W compared to 10.23 mA/W for the Co 2 TiO 4 /n-Si device, and a detectivity of 4.26 × 10 10 Jones, significantly higher than 1.03 × 10 10 Jones for the undoped counterpart. These results demonstrate that ZnO doping significantly improves light absorption, carrier transport, and signal-to-noise ratio, making the Co 2 TiO 4 -ZnO/n-Si photodetector a promising candidate for high-performance, broadband, self-powered photodetection applications.