In:
physica status solidi (a), Wiley, Vol. 210, No. 10 ( 2013-10), p. 2016-2021
Abstract:
We applied time‐resolved nonlinear optical techniques for investigation of carrier recombination and diffusion processes in a 420 μm thick CVD diamond, relatively free from structural and point defects. Injection of 10 15 –10 17 cm −3 carrier density by two‐photon excitation and monitoring free carrier absorption decay in 80–800 K range provided lifetime of 720 ns at T ≥ 300 K. At low temperatures, a linear increase of the carrier recombination rate with the injection level was fitted by an effective bimolecular recombination coefficient B = 10 −11 –10 −9 cm 3 s −1 and attributed to the impact of excitons and biexcitons, contributing to phonon‐assisted indirect Auger recombination. At high temperatures, increase of recombination rate was governed by Coulomb enhanced direct Auger process with a 520 meV threshold. An ambipolar carrier mobility with its peak value of ∼1500 cm 2 V −1 s −1 at room temperature was determined by transient grating technique at ∼2 × 10 15 cm −3 excess carrier density. A strong decrease of mobility at higher injections revealed the role of carrier‐carrier scattering, exciton formation and bandgap renormalization. The simultaneous measurements of carrier lifetime and diffusivity provided carrier diffusion length, which varied in a 1–50 μm range, depending on injection and temperature.
Type of Medium:
Online Resource
ISSN:
1862-6300
,
1862-6319
DOI:
10.1002/pssa.v210.10
DOI:
10.1002/pssa.201300045
Language:
English
Publisher:
Wiley
Publication Date:
2013
detail.hit.zdb_id:
1481091-8
detail.hit.zdb_id:
208850-2
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