Lifetime and quantum efficiency of luminescence due to indirect excitons in a diamond

Optical study of carrier diffusion and recombination in CVD diamond

“…It is to our knowledge the highest measured value. The comparison of exciton lifetime with previous measurements [26] indicates that the observed recombination dynamics is not far from the radiative lifetime of free exciton in diamond. Our results bring new information on free excitons in diamond enhancing its potential in foreseen optoelectronic applications.…”

“…5(a)]. The obtained value of the exciton lifetime is more than 10 Â higher than previously published values measured by one-photon excited time-resolved PL [25,26] and approximately 4 Â higher than the lifetime measured by two-photon excitation with excitation spot size 70 mm [9]. This result draws attention to an important role of diffusion and surface recombination in time-resolved optical measurements.…”

“…5(b)] is almost independent of the sample temperature [see inset of Fig. 5(b)] in contradiction with the data measured by one-photon excited PL [25,26]. The exciton dynamics in diamond can be limited by two factors, namely by the radiative lifetime of free exciton (which is the intrinsic property of pure crystal) and also by the nonradiative impurity-or surface-related recombination.…”

Basic Properties of Diamond: Phonon Spectra, Thermal Properties, Band Structure

“…The lifetime of the exciton has been measured as 2.3 µs [101]. The recombination of the electron and hole must involve a wave-vector conserving phonon (Equation 1.27), and so involves three particles plus the emitted photon (see Section 1.3.3).…”

Emission lines from excitons with collision in indirect semiconductors

“…In a high-density exciton state in diamond of larger than 10 18 cm -3 , it is expected that the exciton-exciton scattering predominates over exciton-phonon scattering or other possible scatterings of excitons [6], and the collision time of exciton-exciton scattering is estimated to be around 10 -12 sec by assuming a scattering cross section of around π(a ex ) 2 , where a ex is the Bohr radius of excitons in diamond [5]. This collision time is sufficiently shorter than the lifetime of the excitons in diamond (10 -8 ~ 10 -6 sec) [7][8][9] and the high-density exciton state in the steady state can be considered to be a quasi-thermal equilibrium state. [6,7].…”