InGaAs-based Gunn light emitting diode
Date
14.02.2023Metadata
Show full item recordAbstract
We report an n-type In0.53Ga0.47As based Gunn light emitting diode operated at around 1.6 μm. The device
structure comprises of an n-type In0.53Ga0.47As epilayer with a thickness of 5 μm grown by Metal Organic Vapour
Phase Epitaxy (MOVPE) on a semi-insulating InP substrate and fabricated in a planar architecture with a stepped
structure at anode side to suppress the destructive effect of high built-in electric field in propagating Gunn
domain. Gunn diode is operated under pulsed voltage with a pulse width of 60 ns and pulse duration of 4.5 ns to
keep the duty cycle as low as 0.0013%. The Gunn oscillations with an 1 ns period are observed at around 4.1 kV/
cm, which corresponds to the electric field threshold of Negative Differential Resistance (NDR). The light
emission at around 1.6 μm also starts at the threshold electric field of the NDR region (E = 4.2 kV/cm) of the
current-voltage curve, and the emission intensity increases drastically with increasing applied electric field. The
observed light emission at NDR threshold electric field where Gunn oscillations appear on the voltage pulse is
attributed to the impact ionisation process occurring in the current domains along the sample, which generates
excess carriers to initiate the band-to-band recombination in In0.53Ga0.47As.