Indian Journal of Science and Technology

Abstract

Objectives: This paper entails the theoretical computation of dark current in asgrown and annealed Quantum Dot Infrared Photodetectors (QDIP). Methods/Statistical analysis: Here, non-equillibrium Green’s function was used to model the dark current characteristics in asgrown and annealed QDIPs. Post-growth thermal annealing, which reduces the traps states in the QD is also simulated using Fick’s second law of diffusion. We have developed a selfconsistent Poisson’s equation solver to compute the potential profile and quasi Fermi level at QD and at the contacts. Findings: The theoretically computed dark current obtained from our model is in good agreement with the experimental data, which validates the efficacy of our model. Our computation also predicts decrease in dark current in the QD with increase in annealing temperature at low bias voltage from0.25-1.5 volts. Application/ Improvements: Here, we have optimized the dark current for different annealing temperatures for improving the performance of QD device for infrared sensing applications
Keywords: Dark Current, Non-Equilibrium Green’s Function, Quantum Dot Photodetectors, Theoretical Modeling