Extended defects in nitride layers, influence on the quantum wells and quantum dots

International audienceFor almost two decades, extensive research has been carried out on wurtzite nitride semiconductors due to their large direct band gap which offer the possibility to produce optoelectronic devices from the infrared (InN) to the ultraviolet range (GaN and AlN). The reduction of the defect densities and polarisation effects in nitride heterostructures are still challenges for the production of efficient light emitting diodes and lasers past the green range. In this contribution, the structure of the extended defects is reviewed, and their possible interaction with quantum wells and quantum dots is discussed. The presence of threading dislocations is shown to constitute a driving force for clustering. Inside semipolar layers, the glide planes are not available for the spreading of perfect dislocations, this results in the formation of a more complex defect system which we have investigated in the case of (11-22) layers