Current Driving Er-Doped Electroluminescence Devices With Long-Term Reliability

An Erbium doped light emitting device characterized with long-term reliability has been realized. The devices are based on npn heterojunction structure which are composed of
${n}^{+}$
-Si/
${p}$
-Si/Er-doped
${n}$
-ZnO. The electroluminescence intensity of Er3+ ions has a well linear relation with operating currents. Meanwhile, the Er3+ ions electroluminescence device with a 3 V onset voltage can keep on operating for more than 1200 hours, attributed to the separation of supply and acceleration of electrons which excite Er3+ ions. Electrons originated from the former
${n}^{+}{p}$
junction diffuse through
${p}$
-Si layer, then they are accelerated in the following space charge region of the latter pn junction to collide with Er3+ ions in ZnO layer. Moreover, the npn heterojunction device structure is also applicable to other rare earths such as Tm, Eu, etc. This strategy will pave a way to electroluminescence of rare earths, and also provide a monolithic silicon light source to integrated silicon photonics.