Study of the charge-accumulation and -relaxation kinetics in a solid dielectric when it is electron-irradiated by an optical method

摘要

This paper discusses the kinetics of the accumulation and relaxation of electric charge in layers of the dielectric MgO + Al2O3 when it is irradiated with electrons having energy 1.6 keV. An optical method is used for the first time, based on the phase modulation of light caused by the electric field of the charge in an electrooptic crystal of deuterated potassium dihydrogen phosphate. It is established that the charge accumulated in the dielectric varies with time according to a linear law when the current density in the beam is 0.28 x 10(-4)-1 x 10(-4) A/cm(2), which corresponds to the electron flux density 1.7 x 10(14)-6 x 10(14) cm(-2). The charge relaxation is significantly accelerated if the charged dielectric is irradiated by an electron beam, creating particles in it with the opposite charge. The positive charge in this case relaxes at a greater rate than does the negative charge. This is apparently because electrons have higher mobility than do holes. (C) 2015 Optical Society of America.