Development of ZnSe-based white LEDs with Longer Lifetime over 10,000hrs

Abstract

We have demonstrated ZnSe-based white LEDs with longer lifetime over 10,000hrs at 14.5A/cm² by introducing an i-ZnMgBeSe/p-ZnMgSe double cladding structure, which combined a very thin i-ZnMgBeSe layer for suppressing electron overflow and p-ZnMgSSe for efficient p-type carrier concentration. By adopting the double cladding layer instead of the conventional p-ZnMgSSe cladding layer, rapid degradation is suppressed and the lifetime tendency is similar to the LEDs consisting of a III-V semiconductor system. The device simulation and the temperature dependence of optical power showed that the i-ZnMgBeSe layer played the main role in increasing electron confinement. Our experimental data and reliability test results indicate that the suppression of the electron overflow is essential to obtain long lifetime acceptable for truly practical use.