Reduction in surface recombination of GaInAsP microcolumns by CH4 plasma irradiation

Abstract

We evaluated the surface recombination velocity vs of 1.55 μm GaInAsP microcolumns through the measurement of carrier lifetime using the phase-resolved spectroscopy. We investigated various surface treatments and confirmed that vs was reduced to nearly half of that for as-etched microcolumns by CH4 electron cyclotron resonance plasma irradiation. This result was ensured by the two- to fivefold increase in photoluminescence intensity. The secondary ion mass spectroscopy analysis suggested that the reduction in vs was attributable to the deposition of a polymer, the hydrogenated hard carbon, etc., and/or a carbon deep level formed near the surface.

Time-resolved lasing action from single and coupled photonic crystal nanocavity array lasers emitting in the telecom band

“…From separate lifetime measurements, we estimate τ nr ≈ 270 ps, which gives S ≈ 3 · 10 4 cm/s. This value is 2-3 times higher than the value of S ∼ 10 4 cm/s reported elsewhere for this material system [12,17], probably due to the processing of the holes. The slower decay of carriers that remain after the first lasing pulse (roughly equal to N tr in the top panel of Fig.3(c)) strongly impacts the dynamics of the second laser pulse, and would lead to eye-closing under a pseudo-random bit sequence.…”

Characterization of bulk and surface currents in strain-balanced InGaAs quantum-well mesa diodes

“…Using the above expressions with the estimated effective n i͑MQW͒ , S is estimated to be 5 ϫ 10 3 cm/ s after the plasma treatment. Prior to the plasma damage this implies S is ϳ3 ϫ 10 2 cm/ s. As this value is lower than values found by other methods 11 it suggests that the effective n i͑MQW͒ is lower or that the thickness ͑d͒ that contributes to the recombination is less than the full thickness of the intrinsic region. To further verify the cause of the increased current the SB-MQW mesa sidewalls were etched in a mixture of H 2 O 2 :H 3 PO 4 :H 2 O in the ratio of 1:1:8 for 30 s. On remeasuring, the current returned to its original value.…”

Improvement in electrostatic-discharge tolerance of 1.3µm AlGaInAs/InP buried heterostructure laser diodes

“…[11][12] We demonstrated effective facet passivation for GaInAsP/InP LDs. This facet passivation was insertion an aluminum thin layer to the interface between the facet coating and the semiconductor facet as shown in figure 7.…”