Auger recombination in strained quantum wells

A nonthreshold mechanism for Auger recombination of nonequilibrium carriers in quantum wells with strained layers is investigated theoretically. It is shown that the dependence of the Auger recombination rate on the magnitude of the strain and the height of the heterobarriers for electrons and holes can be analyzed only by calculating the overlap integrals between initial and final particle states microscopically. In quantum wells with strained layers the presence of strain affects qualitatively and quantitatively the electron-hole overlap integral. The dependence of the Auger recombination rate on the quantum well parameters, the magnitude of the stress, and temperature are analyzed for heterostructures based on InGaAsP/InP and InGaAlAs/InP. Fiz. Tekh. Poluprovodn. 31, 358–364 (March 1997)     

Analysis of electrical, threshold, and temperature characteristics of InGaAsP/InP double- heterojunction lasers

This paper presents an extensive study of the fundamental characteristics of InGaAsP/InP double-heterojunction (DH) lasers with a wavelength of 1.3 μm. The confinement properties of injected carriers in the quaternary active region, the electrical properties such as leakage current and diode current versus voltage, the threshold characteristics, and the threshold temperature characteristics are determined through an analysis of the heterojunction energy band structure. The threshold temperature characteristics and the carrier leakage from the active region into the confining layers are examined in detail. To clarify the dependence of carrier leakage on lasing wavelength in InGaAsP/InP DH lasers and to explain the difference between GaAlAs/GaAs DH and InGaAsP/InP DH lasers, the barrier heights required to effectively confine the injected carriers and the effective carrier masses in the active region are discussed. Various possible explanations for the observed threshold temperature characteristics are considered.     

Interband Auger recombination in InGaAsP

The interband Auger recombination lifetimes of two Auger processes have been calculated to correlate measured threshold current densities and carrier lifetimes for InGaAsP and InGaAsSb lasers. Good aggreement with experimental data was obtained for lasers with low nominal threshold current densities. These results demonstrate the importance of Auger recombination in the threshold characteristics of InGaAsP/InP lasers.     

Threshold characteristics of λ=1.55 µm InGaAsP/InP heterolasers

Temperature dependences of the threshold characteristics of InGaAsP/InP quantum well (QW) lasers have been studied. The main contribution to the threshold current is made by the thresholdless Auger recombination. The observed power-law temperature dependence of the threshold current is explained by the predominance of the thresholdless Auger recombination in QWs over the threshold Auger process.     

Influences of interfacial recombination on oscillation characteristics of InGaAsP/InP DH lasers

This paper presents the influences of interfacial recombination on the oscillation characteristics of InGaAsP/InP DH lasers. The effects of interfacial recombination at the two InP-InGaAsP interfaces, and a theoretical study of the oscillation characteristics such as threshold current density and differential quantum efficiency are discussed and compared with experimental results. The effects of interfacial recombination on the temperature dependence of threshold current are also examined.     

A simple method to determine carrier recombinations in asemiconductor laser optical amplifier

The contribution of nonradiative carrier recombinations to the characteristics of long-wavelength InGaAsP/InP semiconductor laser devices is verified by measuring the amplified spontaneous emission (ASE) power from a 1.5-μm semiconductor laser amplifier (SLA) against the bias current. This method provides a simple and straightforward way to determine the mathematical form of recombination rate in a long-wavelength semiconductor laser, provided that the structural parameters of the laser are known     

Temporal response characteristics of a In0.53Ga0.47As/InP quantum well phototransistor

An investigation of multiple-quantum-well heterojunction phototransistors with InGaAs/InP quantum wells in the collector and InGaAsP base is discussed. The design of the structure ensures that light is absorbed only in the quantum-well region, thus providing a way to study the correlation between quantum well and phototransistor carrier dynamics. Moreover, since the operation of a n-p-n phototransistor is governed by hole injection into the base, the transient behavior of the device reflects the hole dynamics in the multiple-quantum-well region. The response of the device to picosecond optical pulses shows strong dependence on bias conditions: from device response determined by minority carrier recombination time (~2 ns) at high base-emitter bias, to current time constant dominated response (~50 ps) at low base-emitter bias. The field dependent escape times of carriers from the quantum wells under different bias conditions are obtained (10-100 ps) and are seen to affect the risetime of the transistor to pulsed photoexcitation     

Planar surface buried-heterostructure InGaAsP/InP lasers with hydride VPE-grown Fe-doped highly resistive current-blocking layers

The fabrication and lasing characteristics for planar surface buried-heterostructure InGaAsP/InP lasers with highly resistive current-blocking layers are reported. Embedding growth was successfully performed by Fe-doping hydride VPE. Single transverse mode operation has been realised in lasers with a narrow active region, without any nonradiative recombination increase, due to an Fe-associated deep level. High-frequency response up to 10GHz was also demonstrated.     

A planar InP/InGaAsP heterostructure avalanche photodiode

A new guard-ring structure for InP/InGaAsP heterostructure avalanche photodiodes (APD's) is presented. The guard ring consists of a linearly graded junction formed by beryllium ion implantation and two-step InP layers having different carrier concentrations (n-and n-layers grown on an InGaAsP layer). A planar InP/InGaAsP avalanche photodiode having this guard ring has a maximum avalanche gain of 110 at an initial photocurrent of 0.35 µA. The effectiveness of the guard ring is clearly discernible from the spot-scanned photoresponse of the diode.     

低暗计数率InGaAsP/InP单光子雪崩二极管

通过对InGaAsP/InP单光子雪崩二极管（SPAD）的探测效率、暗计数率等基本特性与该器件的禁带宽度、电场分布、雪崩长度、工作温度等参数之间关系的分析,采用比通常的InxGaAs （x=0.53）材料具有更宽带隙的InxGa1-xAsyP1-y（x=0.78,y=0.47）材料作为光吸收层,并且精确控制InP倍增层的雪崩长度,有效地降低了SPAD的暗计数率。其中InGaAsP材料与InP材料晶格匹配良好,可在InP衬底上外延生长高质量的InGaAsP/InP异质结,InGaAsP材料的带隙为Eg=1.03 eV,截止波长为1.2 m,可满足1.06 m单光子探测需要。同时,通过设计并研制出1.06 m InGaAsP/InP SPAD,对其特性参数进行测试,结果表明,当工作温度为270 K时,探测效率20%下的暗计数率约20 kHz。因此基于时间相关单光子计数技术的该器件可在主动淬灭模式下用于随机到达的光子探测。     

带有阶梯缓变集电区的InP/InGaAs/InP DHBT材料研究

设计并生长了一种新的InP/InGaAs/InP DHBT结构材料,采用在基区和集电区之间插入两层不同禁带宽度的InGaAsP四元系材料的阶梯缓变集电结结构,以解决InP/InGaAs/InP DHBT集电结导带尖峰的电子阻挡效应问题。采用气态源分子束外延(GSMBE)技术,通过优化生长条件,获得了高质量的InP、InGaAs以及与InP晶格相匹配的不同禁带宽度的InGaAsP外延材料。在此基础上,成功地生长出带有阶梯缓变集电区结构的InP基DHBT结构材料。     

A vertical monolithic combination of an InGaAsP/InP laser and a heterojunction bipolar transistor

A DH InGaAsP/InP mesa laser and a DH InGaAsP/InP mass-transport laser were successfully put together with an InGaAsP/InP heterojunction bipolar transistor in a vertical configuration. A laser threshold current as low as 17 mA and an output laser power of over 30 mW were achieved. Base injection current-controlled optical bistability and optical switching were demonstrated.     

1．55μm InGaAsP／InPDH激光器中的0．95μm发光带与Auger复合

报道了在１．５５μｍＩｎＧａＡｓＰ／ＩｎＰ激光器中发现的０．９５μｍ波长高能发光峰的一系列实验结果，并通过分析肯定了ＩｎＧａＡｓＰ有源区的Ａｕｓｅｒ复合是造成载流子向两侧ＩｎＰ限制层漏泄的主要原因，也是影响１．５５μｍＩｎＧａＡｓＰ／ＩｎＰＤＨ激光器Ｔ０值的主要因素。     

A numerical calculation of auger recombination coefficients for InGaAsP/InP quantum well heterostructures

Auger recombination coefficients are calculated numerically for InGaAsP/InP quantum well heterostructures. In narrow quantum wells, the quasi-threshold and thresholdless mechanisms mainly contribute to the Auger recombination coefficient. For the processes involving two electrons and a heavy hole (CHCC) or an electron and two heavy holes with a transition of one of the holes to the spin-orbit split-off band (CHHS), the Auger recombination coefficients depend on temperature only slightly in a wide temperature range. The dependence of the Auger coefficient on the quantum well width is analyzed and found to be nonmonotonic.     

Room temperature c.w. operation of InGaAsP/InP heterostructure lasers emitting at 1.56 ?m

Room-temperature c.w. operation of InGaAsP/InP heterostructure lasers grown by liquid-phase epitaxy was achieved at 1.56 ?m. An active InGaAsP layer was essentially sandwiched by InP, though a thin InGaAsP buffer layer was deposited to prevent the melt-back of the active layer. Threshold current was typically 300 mA for a 17 ?m wide oxide-defined stripe laser.     

Auger recombination rates in compressively strainedInxGa1-xAs/InGaAsP/InP(0.53⩽x⩽0.73) multiquantum well lasers

The authors have experimentally determined Auger recombination rates in compressively strained In_xGa_1-xAs/InGaAsP/InP MQW lasers for the first time. The Auger recombination rates were derived from the measured turn-on delay times during large-signal modulation of single-mode lasers. The Auger coefficient increases from 5±1×10^-30 to 13±1×10^-30 cm⁶ s^-1 as the indium composition in the quantum well active region, x, increases from 0.53 to 0.73     

Compensation of internal thermal stresses in InGaAsP/InP lasers for polarization stabilization

Internal thermal stresses in the active layer of a conventional InGaAsP/InP laser may cause polarization instabilities which normally do not exist in conventional AlGaAs/GaAs lasers. We analyze a structure with a buffer layer for Polarization stabilization by compensation of the internal thermal stresses in InGaAsP/InP lasers. Stress analyses are carried out for various structures to obtain the conditions for optimal stress-free structures. The effects of stresses from external sources are also discussed.     

InGaAsP/InP双异质结发光管中的深能级

本文用DLTS谱仪研究了SiO2限制的InGaAsP/InP双异质结发光管中的深能级。结果表明:只有在p-n结位于p-InP/n-InGaAsP界面处的个别器件中,有△E=0.24eV的多子陷阱。     

Facet oxidation of InGaAsP/InP and InGaAs/InP lasers

The facet oxidation of InGaAsP/InP and InGaAs/InP lasers is investigated after aging under high constant optical output power or high current stress. Facet oxidation in InGaAsP/InP lasers is negligibly small under several thousand hours of practical operation. The thickness of oxide film increases in proportion to optical output power and logarithm of aging time. The growth rate of facet oxide film weakly depends on the junction temperature and the activation energy is estimated to be 0.07 eV within a experimental range between 25 and 150°C. The facet of InGaAs/InP lasers are oxidized more easily than that of InGaAsP/InP lasers but are about two orders of magnitude more stable against oxidation than that of AlGaAs/GaAs lasers.     

The growth of high quality InP/InGaAs/InGaAsP interfaces by CBE for SCH multi-quantum well lasers

Bulk InGaAsP and heterointerfaces of InP/InGaAs and InGaAsP/InGaAs have been grown by chemical beam epitaxy for use in multi-quantum well separate confinement heterostructure lasers. InGaAsP has been successfully grown for λ=1.1, 1.2 and 1.4 μm. The TMI and TEG incorporation coefficients have strong dependencies on substrate temperature and also charge as the InGaAsP composition tends towards InP. InP/InGaAs and InGaAsP/InGaAs quantum wells have been grown to determine the optimum gas switching sequence to minimize the measured photoluminescence FWHM. InGaAs quantum wells as narrow as 0.6 nm have been grown with 7K FWHM of 12.3 meV. Lattice matched MQW-SCH lasers were grown using different interface switching sequences with the best laser having a threshold current density of 792A/cm² for an 800 × 90 μm broad area device.