Enhanced Photosensing Characteristics of Al/Mg co-doped CdS CQDs Photodetectors for Visible to NIR detection

Author : Tania Kalsi, Pragati Kumar

Abstract :Development highly performed photodetectors (PDs) using wide band gap semiconductors is a significant field of research in the present scenario. This research investigates the fabrication and performance evaluation of multi-ion doped photodetectors, particularly in the visible to NIR spectrum, utilizing Al/Mg co-doped CdS colloidal quantum dots thin films (CQDs TFs). The Al/Mg co-doped CdS QDs were synthesized using chemical co-precipitation method, followed by the deposition of TFs on p-type silicon substrates by spin coating method. Comprehensive electrical measurements were conducted to assess the devices’ performance under varying illumination wavelengths. The results reveal that co-doping significantly enhances the detectivity (D) and responsivity (R) of the PDs. The device exhibited the highest detectivity value of 4.57 x 1013cmHz1/2W-1 under 845 nm illumination, indicating superior performance in the NIR region. Additionally, the maximum R values is estimated to be 11.31 AW-1 with optimal performance achieved at a bias voltage of 5V. The results demonstrate that the incorporation of both ions effectively improves the photosensing capabilities of CdS-based PDs, paving the way for advanced applications in optoelectronic devices. This study contributes to the understanding of co-doping strategies in enhancing the performance of semiconductor PDs, with implications for future research and development in the field.

Keywords :Photodetectors, wide band gap semiconductors, CdS quantum dots, Al/Mg co-doping, thin films, spin coating, detectivity,

Conference Name :International Conference on Nanotechnology and Functional Materials (ICNFM-24)

Conference Place Rome, Italy

Conference Date 12th Dec 2024