Carrier capture and escape processes in In/sub 0.25/Ga/sub 0.75/As-GaAs quantum-well lasers

Abstract

We have extracted the ratio between the carrier capture and escape times, , for In 0:25 Ga 0:75 As-GaAs lasers containing one, two, or three quantum wells, from high-frequency subthreshold impedance measurements at different temperatures. Our results show that the carrier capture process dominates over the diffusion along the confinement region in the overall transport/capture process. The obtained value for is comparable to unity, and this fact has to be taken into account to obtain real material parameters, such as the carrier lifetime and the radiative recombination coefficient.

Analysis of carrier dynamic effects in transistor lasers

“…12 The carrier escape time from QW can be calculated by [12][13][14] In general, τ capi is about 0.3 to 0.5 ps for typical QW lasers.…”

Quantum Well Saturation Effect on the Reduction of Base Transit Time in Light-Emitting Transistors

“…where W B is the base region width, L W is the single QW width (W B = 1358 Å, L W = 112 Å), and the τ cap0 is the intrinsic or local capture time, which could ranges from 0.2 to 0.6 ps [11], [16], [17], [24]. According to (5), τ cap in our case is 2.4-7.3 ps for single QW.…”

Simple model for calculating the ratio of the carrier capture and escape times in quantum-well lasers

“…9 By analyzing samples with the same active material but different number of QWs, we were able to extract the ratio cap / esc . 10 Table I summarizes The measured values of esc and of the ratio cap / esc can be qualitatively understood considering that the electrons, not the holes, are responsible for the dynamic response of the devices. This follows from a comparison of esc at a constant-carrier density for the In 0.35 Ga 0.65 As lasers with different p-doping concentrations in the active regions ͑samples A-C͒.…”