Performance of ZnO Quantum Dots Based Photodetectors: Effect of Metal Electrodes

The fabrication and characterizations of ZnO quantum dots (QDs) based interdigitated metal-semiconductor-metal (MSM) photodetector using different electrode metals is reported in this work. The colloidal ZnO QDs used for the photodetection have an average particle size of ~2.53 nm. The interdigitated pattern of gold (Au), silver (Ag), and aluminum (Al) metals are formed over ZnO QDs. The comparative study of these metal electrodes is carried out in terms of I-V characteristics, time response, responsivity, and stability under dark and UV illumination. It is found that the photodetector using Au interdigitated electrode has better electrical and optical performance as compared to Ag and Al electrodes.