Efficient electroluminescence from rare earth doped MOS diodes

Efficient infra-red and visible electroluminescence (EL) has been obtained from implanted rare earth ions in the SiO2 of a silicon-metal-oxide-semiconductor (MOS) diode structure at room temperature. The rare earth ions are excited by the direct impact of hot electrons tunneling through the oxide at electric fields larger than 6 MV cm−1. The internal quantum efficiencies of Er and Tb implanted MOS diodes are estimated at 10 and 3%, respectively. The high quantum efficiency is due to the high impact excitation cross-section >10−15 cm−2. These observations on MOS structures are an experimental proof for efficient light generation by hot electron impact.