Dark current assessment in Colloidal Quantum Dots

The Challenge

Colloidal Quantum Dots (CQDs), especially lead sulfide (PbS)-based systems, are attracting strong interest for infrared (IR) detection owing to their bandgap tunability and solution-processable nature. However, the dark current in CQD-based photodetectors remains a major limitation for real-world applications, significantly impacting detectivity and power consumption.

Understanding and modeling the physical mechanisms behind dark current—such as thermal generation, field-assisted tunneling, trap-assisted hopping, and interfacial leakage—are essential for designing high-performance devices. In this internship, you will focus on developing analytical and numerical models to describe and predict dark current behaviors in various CQD device architectures, guided by experimental observations. 

What You Will Do

• Conduct a comprehensive literature review on dark current phenomena in CQD photodetectors.
• Build compact physical models to analyze thermionic emission, Shockley–Read–Hall generation, trap-assisted tunneling, and field emission.
• Implement numerical simulations (e.g., using TCAD, Python, or MATLAB) to explore the parameter space and simulate current–voltage characteristics under varying bias and temperature conditions.
• Use available experimental data to validate your models and extract relevant physical parameters (e.g., trap density, mobility, activation energy).
• Investigate the influence of device stack configurations and energy level alignments on dark current suppression.
• Summarize findings in technical reports and prepare materials for publication or presentation.