An Auger defect, also known as Auger recombination, refers to a phenomenon observed in solid-state materials, particularly semiconductors, where electron-hole recombination occurs via a non-radiative process. The term "Auger" originates from the name of the Italian physicist, P.A. Auger, who discovered this process in the early 20th century.
In a typical radiative recombination process, an excited electron in the conduction band recombines with a hole in the valence band, emitting a photon as a result. However, in certain materials, due to specific energy levels and band structures, a non-radiative recombination pathway becomes dominant. This occurs when an excited electron in the conduction band transfers its excess energy to another electron in the valence band, causing it to be ejected out of the material. This ejected electron is commonly referred to as an Auger electron.
Auger defects can be detrimental to the performance of semiconductor devices, especially in optoelectronic applications like light-emitting diodes (LEDs) or solar cells, as it reduces the efficiency of electron-hole recombination and hence leads to lower emission or conversion of light. Efforts are made in material engineering and device design to minimize the occurrence of Auger defects, such as tailoring the bandgap, optimizing doping levels, or utilizing specific nanostructures to mitigate non-radiative recombination.
Understanding and mitigating Auger defects is crucial for the development of high-efficiency and high-performance semiconductor devices, where maximum utilization of electron-hole recombination is desired for optimal operation.
