Blue-green light emitting diodes with new p-contact layers: ZnSe/BeTe

We have fabricated ZnCdSe/ZnMgBeSe single quantum well (SQW) light emitting diode (LED) structures with ZnSe:N/BeTe:N p-contact layers. The electrical properties of this p-contact layer scheme were evaluated for the use in Zn Se-based II-VI LDs. The specific contact resistance for Au/p-ZnSe/p-BeTe oh mic contact layers, which was measured by the transmission line model (TLM) method, was as low as 4.2 x 10(-4) Ohm cm(2) even without annealing when t he ZnSe layer thickness is 5 nm. The composition of quaternary ZnMgBeSe was determined using a ZnBeSe/ZnMgBeSe layer structure by PL and X-ray measure ments. The p-type doping property was investigated for ZnMgBeSe with differ ent compositions, and N-a-N-d drastically decreases with increasing band ga p energy the same as that of the ZnMgSSe:N system. The fabricated LEDs show a strong electroluminescence under de bias at room temperature.