On the correctness of mathematical models of time-of-flight cathodoluminescence of direct-gap semiconductors

Two-dimensional and three-dimensional mathematical models of diffusion and cathodoluminescence of excitons in single-crystal gallium nitride excited by a pulsating sharply focused electron beam in a homogeneous semiconductor material are compared. The correctness of these models has been carried out, estimates have been obtained to evaluate the effect of errors in the initial data on the distribution of the diffusing excitons and the cathodoluminescence intensity.

Радиационная деградация сцинтилляторов на основе LiF : W

Patterns and causes of changes in spectral-kinetic characteristics of the cathodoluminescence in LiF: W crystals are studied under irradiation by nanosecond electron pulses. The contribution of the transformation processes of pre-radiation imperfection and accumulation of color centers to cathodoluminescence distortion is revealed. Optimal operating conditions for LiF:W scintillators are determined. It is found that pre-irradiation of LiF:W with doses of 103–104 Gy causes 1.5–2 fold increase in cathodoluminescence intensity (low dose effect).

Characterization of Plasma Induced Damage and Strain on InP Patterns and Their Impact on Luminescence

ABSTRACTThe effect of damage induced by plasma etching on the cathodoluminescence intensity of micron-size InP features is studied. At the etched bottom, it is found that the hard mask stripping process is sufficient to recover the luminescence. Within features, the presence of sidewalls reduces luminescence intensity due to additional non-radiative surface recombinations. For a n-doped sample, a carrier diffusion length of 0.84 μm and a reduced nonradiative surface recombination velocity of 2.58 are calculated. Hydrostatic strain within the etched features is measured using the peak shift of the luminescence signal, while in plane strain anisotropy is obtained from its degree of polarization, both with a resolution of about 100 nm.