研究目的
To analyze the optical properties of InAs1?xSbx/Aly In1?y As quantum wells (QWs) grown by molecular beam epitaxy on relaxed Aly In1?y As metamorphic buffer layers (MBLs) using GaAs substrates, and to evaluate their potential for applications in mid-infrared light-emitting diodes and diode lasers.
研究成果
The study concludes that InAs1?xSbx/Aly In1?y As metamorphic QWs grown on GaAs substrates offer a promising route for developing LEDs or diode lasers with good performance in the 3–4 μm spectral range. The compressive strain in the QWs enhances radiative efficiency by reducing the band edge density of states, making more carriers available for radiative recombination. Further studies are needed to quantify loss mechanisms and design optimized structures for practical applications.
研究不足
The study identifies that achieving longer emission wavelengths requires higher Sb compositions, which can degrade electron confinement. Additionally, the presence of non-radiative recombination mechanisms, likely Auger recombination, limits the overall radiative efficiency of the structures.
1：Experimental Design and Method Selection:
The study involves the growth of InAs1?xSbx/Aly In1?y As QWs by molecular beam epitaxy (MBE) on GaAs substrates using relaxed Aly In1?y As MBLs. The optical properties are analyzed through photoluminescence (PL) measurements and theoretical calculations based on an eight-band k·p Hamiltonian.
2：Sample Selection and Data Sources:
The samples consist of five-period InAs1?xSbx/Al0.125In0.875As multi-QW layers with Sb compositions up to x = 10%. The structures are characterized by double-crystal x-ray diffraction (DC-XRD), atomic force microscopy, and transmission electron microscopy (TEM).
3：125In875As multi-QW layers with Sb compositions up to x = 10%. The structures are characterized by double-crystal x-ray diffraction (DC-XRD), atomic force microscopy, and transmission electron microscopy (TEM).
List of Experimental Equipment and Materials:
3. List of Experimental Equipment and Materials: A Veeco GENxplor MBE system is used for growth, with valved cracker cells for As2 and Sb2 fluxes, and thermal effusion K-cells for In and Al fluxes. PL measurements are performed using a 785 nm diode-pumped solid state laser and a Bruker Vertex 70 Fourier transform mid-infrared spectrometer.
4：Experimental Procedures and Operational Workflow:
The structures are grown at specific temperatures for each layer, with in situ reflection high-energy electron diffraction used to monitor surface reconstruction. PL measurements are carried out at temperatures ranging from 4 to 300 K.
5：Data Analysis Methods:
The theoretical model calculates the QW spontaneous emission (SE) spectra, using material parameters recommended by Vurgaftman et al., and compares these with the measured PL spectra to analyze the electronic and optical properties.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
