Estimation of the acceleration ability for electrons in SiO2 and the tunneling effect

Silicon dioxide (SiO2) plays an important role in layered optimization scheme and solid-state cathodoluminescence (SSCL). Initially, it was believed that the SiO2 layer would (i) generate extra interface states contributing to a number of primary electrons available for exciting the luminescent centers, and/or (ii) act as acceleration layer resulted in gaining high energy for those electrons that would tunnel into the luminescent layer to excite luminescent centers. Based on the brightness vs. voltage (B–V) measurements, we deem that the latter case, i.e. acceleration and tunneling, is the dominant mechanism. A detailed discussion in terms of electrons acceleration and tunneling as the main contributions to the enhancement of brightness is presented.