Electronic Band Structure Of Phosphorus-Doped Single Crystal Diamond: Dynamic Jahn-Teller Distortion Of The Tetrahedral Donor Ground State

The electronic band structure of the phosphorus-doped high-quality high-pressure and high-temperature-grown single crystal diamond was studied by infrared absorption, magneto- and electron paramagnetic resonance spectroscopy, and first-principles calculations. The complete picture of the 1s -> np(+/-) and 1s -> np(0) (n = 2, 3, 4) donor transitions with new 1s -> 3p(0),4p(0) and 1s -> 4p(+/-) transitions allowed us to refine the energy levels of ground and exited states with those obtained from effective mass approximation calculation. For the first time, as far as we know, we have observed the fine doublet structures of the 1s(B-2, E) -> 2p(+/-), 1s(B-2, E) -> 1s(B-2, E) -> 3p(+/-), and 1s(B-2, E) -> 4p(+/-) donor transitions with the splitting value of 1.05 meV. These doublet structures arise from the dynamic Jahn-Teller (JT) distortion which splits the energy level of the 1s(T-2) state in the T-d configuration into those of the 1s(B-2) ground state and the 1s(E) state in the D-2d configuration. The dynamic JT distortion of the tetrahedral donor ground state has been proved by following facts: the observation of vibronic energy levels and temperature behavior of doublet bands in the IR spectrum, the absence of P-donor-related electron paramagnetic resonance signals, and first-principles calculations. We believe that the dramatic broadening of the 2p(0) band attributed to the 1s(B-2, E) -> 2p(0) donor transition at 524 meV is caused by the resonant interaction of this 524 meV energy level with that of similar to 517 meV formed due to the dynamic JT coupling of the 1s(E) energy level equal to 387 meV with the longitudinal acoustic phonon of similar to 130 meV.