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The Shockley-Read-Hall recombination process generally occupies the net rate of recombination in low quality materials having high density of defects.

For single-energy level traps the SRH rate of volume recombination, USRH, is expressed as:

(1.56)

Where τ_n0 and τ_p0 are the electron mean carrier lifetime and hole mean carrier lifetime, respectively, and are associated to the charge carrier thermal velocity, v_th, the concentration of defect, N_T, and the capture cross-sections of electron and capture cross-sections of hole of the specific defect, σ_n and σ_p as

n₁ and p₁ are defined as:

(1.57)

According to definition, n₁ and p₁ are the free-electron and free-hole concentrations when the Fermi level (EF) lies at the trap energy level (ET).

Actually, all three recombination processes deliberated here occur simultaneously.

The net recombination can be found by addition of the three rates of recombination as:

(1.58)