Injection and temperature dependent carrier recombination rate and diffusion length in freestanding CVD diamond

Abstract

We applied time-resolved nonlinear optical techniques for investigation of carrier recombination and diffusion processes in a 420 mm thick CVD diamond, relatively free from structural and point defects.

Hot-carrier transport in diamond controlled by femtosecond laser pulses

“…We also measured the dependence of LITG dynamics on initial excited carrier density at different sample temperatures. From previous studies [21,24], the role of carrier-carrier scattering in carrier diffusion in diamond is well known. Our aim was to study how hot-carrier diffusion dynamics is influenced by this scattering mechanism.…”

“…There are two reasons why the hot-carrier diffusion was not observed in former measurements of LITG in diamond [21][22][23][24]. First, in most published papers, the picosecond laser pulses were used for LITG excitation and detection of diffraction efficiency.…”

“…Due to the low diffraction efficiency by the thin grating produced by above-band gap excitation, diffusion at high carrier densities was investigated (10 16 -10 19 cm −3 ). Typical observed grating decay times with the grating period Λ = 2-5 μm are 5-500 ps and they depend on carrier density, sample temperature, and amount of impurities [21][22][23][24]. Dynamics of electrons from different conduction band valleys can possibly be observed by this experimental technique only when the intervalley scattering time is longer than the measured LITG dynamics.…”

“…There are several publications dealing with optical measurements of ambipolar diffusion in diamond using the LITG technique [21][22][23][24]. Due to the low diffraction efficiency by the thin grating produced by above-band gap excitation, diffusion at high carrier densities was investigated (10 16 -10 19 cm −3 ).…”

Features of free carrier and exciton recombination, diffusion, and photoluminescence in undoped and phosphorus-doped diamond layers

“…Here  R0 is the bulk trap related lifetime (we assumed it to be 800 ns as in bulk CVD diamonds [1,2]), B = B rad + B nonrad is the quadratic recombination coefficient (consisting from radiative, B rad , and nonradiative, B nonrad , parts (arising due to trap-assisted [29] or Coulomb(exciton)-enhanced Auger recombination [30,31])), and C FC is the free carrier Auger recombination coefficient [11].…”