Interface structure
A central goal of modern artificial heterostructures is the control of interfaces due to their crucial effect on both physical properties and device performance. High-resolution and analytical TEM techniques are used to determine quantitatively the interface roughness and chemical intermixing contributing to the interface “width”. Systematic studies on the correlation between these interface properties, the growth conditions and the optical properties are in focus of our research and have been successfully carried out on several III-V semiconductor heterostructure systems
Example:
(In,Ga)(N,As) quantum wells (QW) embedded in GaAs are used as active zones in lasers for telecommunication. Depending on the growth conditions, the In concentration profile across the QW reveals a remarkable segregation. The fitting curve represents a theoretical calculation that includes Muraki´s model for segregation inside the QW and a specific interface-related part based on a sigmoidal law, from where the interface width is inferred (see figure).
