Generalized A(n)BC Recombination Model in Semiconductors with Multilevel Defects

Area of Science:

• Semiconductor physics
• Materials science
• Computational materials science

Background:

• The ABC model assumes linear dependence of recombination rate on excess carrier density (Δn), using a constant coefficient A.
• Multilevel defects in semiconductors can alter charge state distributions with varying Δn.
• Previous studies often neglect carrier emission from defect levels, impacting recombination rate calculations.

Purpose of the Study:

• To investigate the impact of carrier emission from multilevel defects on recombination rates.
• To demonstrate the inadequacy of the linear ABC model for such defects.
• To propose a revised model, A(n)BC, accounting for defect dynamics.

Main Methods:

• Computational modeling of carrier capture and emission dynamics in multilevel defects.
• Analysis of defect charge state distributions under varying excess carrier densities.
• Case studies on VGa-ON in GaN and PbI in CsPbI3.

Main Results:

• Carrier emission significantly alters defect charge state distributions.
• The recombination coefficient A becomes dependent on Δn, i.e., A(n).
• Neglecting carrier emission can lead to underestimation of recombination rates by over 8 orders of magnitude.

Conclusions:

• The recombination rate in semiconductors with multilevel defects is nonlinear with Δn.
• The ABC model requires reformulation to A(n)BC to accurately describe defect-assisted recombination.
• Future studies on multilevel defects must include carrier emission for accurate results.