1.54 μm Light emitting devices based on Er/O-doped Si layered structures grown by molecular beam epitaxy

Abstract Two types of Si:Er light emitting devices have been processed and characterized with an aim to efficiently use hot electrons for impact excitation. One is a p+-SiGe/i-Si/n-Si:Er:O/n+-Si tunneling diode with a design favoring electron tunneling from the SiGe valence band to the Si conduction band and subsequent acceleration. Another type of Si:Er light emitters is based on a heterojunction bipolar transistor (HBT) structure containing an Er-doped active layer in the collector. In these devices, one can introduce hot electrons from the HBT emitter in a controlled way with a collector bias voltage prior to the avalanche breakdown to improve the impact excitation efficiency. Intense electroluminescence was observed at 300 K at low current (0.1 A cm −2 ) and low bias (3 V). An impact cross-section value of 1×10 −14 cm 2 has been estimated, which is a 100-fold increase compared with the values reported from any other type of Er-doped LEDs.