Dear Mr. Sen,

welcome,

The Band- Band Auger recombination is a three particle process where two electrons and hole can collide with each other simultaneously, one electron recombines with the hole and the free recombination energy is given to the other electron as a kinetic energy. It could be also occurs when two holes and one electron collide with other where one hole recombines with the electron and the other hole acquires the free energy of the recombination. The rate of this process is proportional to either to n^2p or np^2, The consonant of this reaction rate is the Auger recombination recombination constant. It depends on the energy band structure of the material. It is an intrinsic property of the material.

However, there is also band impurity band indirect Auger recombination which depends of trap density in the material in addition to its energy band structure.

The recombination mechanism are studied by Shockley , Read and Hall and they appropriate rate equations for the different mechanisms.

I would like to follow this topic in my book: Book Electronic Devices

Best wishes

As the previous reply correctly states, there are Auger processes that involve defect states. In typical III-V materials for wavelength in the IR (>800nm) the so-called direct Auger processes dominate. These do only depend on the ideal crystal bandstructure and wavefunctions and are a material property. The direct Auger processes generally decrease in strength with increasing bandgap. In materials for the visible and UV (AlInGaN) the direct processes become so small that they have virtually no impact on device performance and radiative and SHR defect recombination dominate. Here, Auger processes that include defect states for momentum conservation can become a bit more relevant, but are still generally weak. Instead Auger processes that involve phonons become the dominant Auger processes. As the direct processes, these are intrinsic to the material and not dependent on the material quality. The importance of these processes for device performance is still a topic of debate.

In my opinion, an Auger coefficient of 10^-40 cm^6/s is not realistic for any material. Even in the wide bandgap materials the direct Auger coefficient is of the order of 10^-34 and processes involving phonons have a similar or even larger rate. For any realistic device operation conditions a coefficient of 10^-40 would lead to losses that would be totally dominated by conventional SHR defect recombination and radiative recombination losses. Thus, it would be impossible to ever measure such a small coefficient.

Go through the attached article to find the answer:

Findlay, P.C., Pidgeon, C.R., Kotitschke, R., Hollingworth, A., Murdin, B.N., Langerak, C.J.G.M., van Der Meer, A.F.G., Ciesla, C.M., Oswald, J., Homer, A. and Springholz, G., 1998. Auger recombination dynamics of lead salts under picosecond free-electron-laser excitation. Physical Review B, 58(19), p.12908.