Double injection in Si:In devices

Abstract

The current-voltage characteristics of Si:In double-injection devices were measured up to breakdown in the temperature range 20–80 K. To vary the amount of optical carrier generation the devices were either exposed to a 50 K cold shield or a 300 K background. The breakdown voltages were found to be strongly dependent on device temperature and irradiation intensity. By using simple analytical expressions it is shown that the unexpected low values at high temperatures or at high irradiation levels are due to large densities of thermally or optically generated holes. To obtain a satisfactory agreement between theory and experiment the regional approximation method is employed. The analysis extends previous treatments by taking into account field-dependent mobilities and capture coefficients. The description of the prebreakdown characteristics includes also the lowering of the ionization energies of the acceptor centers at high field strengths.