Auger Recombination In Quantum Research Articles

Auger Recombination in Quantum Well Laser with Participation of Electrons in Waveguide Region

Abstract A new mechanism of nonradiative recombination of nonequilibrium carriers in semiconductor quantum wells is suggested and discussed. For a studied Auger recombination process the energy of localized electron-hole pair is transferred to barrier carriers due to Coulomb interaction. The analysis of the rate and the coefficient of this process is carried out. It is shown, that there exists two processes of thresholdless and quasithreshold types, and thresholdless one is dominant. The coefficient of studied process is a non-monotonous function of quantum well width having maximum in region of narrow quantum wells. Comparison of this process with CHCC process shows that these two processes of nonradiative recombination are competing in narrow quantum wells, but prevail at different quantum well widths.

Area- and Thickness-Dependent Biexciton Auger Recombination in Colloidal CdSe Nanoplatelets: Breaking the “Universal Volume Scaling Law”

Colloidal nanoplatelets (NPLs) have shown great potentials for lasing applications due to their sharp absorption and emission peaks, large absorption cross sections, large radiative decay rates, and long multiexciton lifetimes. How multiexciton lifetimes depend on material dimensions remains unknown in two-dimensional (2D) materials, despite being a key parameter affecting optical gain threshold and many other properties. Herein, we report a study of room-temperature biexciton Auger recombination time of CdSe NPLs as a function of thickness and lateral area. Comparison of all NPLs shows that the biexciton lifetime does not increase linearly with volume, unlike previously reported "universal volume scaling law" for quantum dots. For NPLs of the same thickness (∼1.8 nm), the biexciton lifetime increase linearly with their lateral area (from 143.7 ± 12.6 to 320.1 ± 17.1 ps when the area increases from 90.5 ± 21.4 to 234.2 ± 41.9 nm2). The biexciton lifetime depends linearly on (1/Ek(e))7/2 (Ek(e) is the electron confinement energy) or nearly linearly on d7 (d is NPL thickness). The observed dependence is consistent with a model in which biexciton Auger recombination rate scales with the product of exciton binary collision frequency and Auger recombination probability in biexciton complexes. The linear increase of Auger lifetimes with NPL lateral areas reflects a 1/area dependence of the binary collision frequency for 2D excitons and the thickness-dependent biexciton Auger recombination time is attributed to its strong dependence on the degree of quantum confinement. This model may be generally applicable to exciton Auger recombination in quantum confined 1D and 2D nanomaterials.

DC and Dynamic Characteristics of P-Doped and Tunnel Injection 1.65-$\mu{\hbox {m}}$ InAs Quantum-Dash Lasers Grown on InP (001)

We have studied the characteristics of 1.65-mum InAs self-organized quantum-dash lasers grown on InP (001) substrates, wherein special techniques of p-doping of quantum dashes and tunnel injection are incorporated for the first time. We measured a very large T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> (196 K) in p-doped quantum-dash lasers, accompanied by an increase in threshold current density (J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> ~1600 A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2 </sup> ), compared to the undoped quantum-dash lasers (T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> =76 K and J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> ~950 A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ). The p-doped lasers exhibit a maximum 3-dB bandwidth of 8 GHz, chirp ~1.0 Aring, and alpha-parameter ~1.0 (measured at subthreshold bias conditions) at a temperature of 278 K. Similar undoped quantum-dash lasers exhibit a 3-dB bandwidth of 6 GHz. A self-consistent model, that includes Auger recombination in quantum dashes, is developed to calculate the threshold current at various temperatures. A comparison of the calculated threshold current and T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> with measured values reveals that Auger recombination in quantum dashes plays a major role in determining the values of threshold current and T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> in both undoped and p-doped quantum-dash lasers. While p-doping increases the gain and differential gain, the presence of wetting layer states, the relatively large inhomogeneous broadening of quantum dashes, and the substantially increased Auger recombination upon p-doping severely limit the potential benefits. Superior characteristics, including large modulation bandwidth (f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3 dB</sub> ~12 GHz), near-zero alpha-parameter, and very low chirp (~0.3 Aring), are achieved when the technique of tunnel injection is also utilized

Auger recombination in quantum well semiconductors: calculation with realistic energy bands

Auger recombination (AR) in quantum well (QW) semiconductors is re-investigated taking into account a realistic band structure instead of the usual parabolic approximation. Since direct AR is negligible in QWS phonon-assisted AR is treated. The theoretical results are in good agreement with experimental investigations. In contrast, the description of QWS by a reduced heavy-hole mass is insufficient. The influence of AR on the temperature dependence of semiconductor lasers is discussed.

Phonon-assisted auger recombination in quantum well semiconductors

Phonon-assisted Auger recombination (AR) is shown to be an important loss mechanism in a quantum well semiconductor in addition to the direct AR. Theoretical investigations demonstrate that it is of the same order of magnitude and has the same temperature dependence as in bulk material, just as direct AR, provided that the material parameters and the carrier concentrations are the same as in the bulk.

Auger recombination in quantum well InGaAs

The application of a realistic band structure shows that phonon-assisted Auger recombination with its weak temperature dependence dominates in quantum well semiconductors, a result in contrast to bulk materials. The experimental result where the Auger coefficient of quantum well InGaAs is nearly temperature independent is explained.

Auger recombination in quantum well gallium antimonide

The temperature dependence of Auger recombination in quantum well GaSb is investigated. The result is a similar behaviour to that in bulk GaSb, increasing at low temperatures and decreasing at high temperatures with a maximum in between. This temperature dependence suggests a minimum in the temperature dependence of the gain whereas experiment gives a monotonic decrease. This discrepancy is resolved, showing that the gain measurements correspond to the increasing branch of the Auger curve.

Theory of Auger recombination in a quantum well wire

Calculations are presented for the rate of Auger recombination in a semiconductor quantum well wire. An expression is given for the rate of the CHSH Auger process in which the carriers remain in their ground subbands, and the rates of other processes such as CHCC may be obtained by simple algebraic substitution. Numerical calculations that consider all possible bound-to-bound intra- and inter-subband transitions are reported. Results are given for the rate of the CHCC process as a function of wire width and wire axis direction for an InGaAsP/InP quantum well wire.