Properties of gas source molecular beam epitaxy grown wavelength extended InGaAs photodetector structures on a linear graded InAlAs buffer

Abstract

The properties of gas source molecular beam epitaxy grown wavelength extended (2.4 μm) InGaAs photodetector structures on a linear graded InAlAs buffer with different grading rates have been investigated by means of XRD and PL techniques in conjunction with optical and atomic force microscopy. Results show that full relaxation and favorable optical characteristics of the active layers only occur for the wafers with a mismatch grading rate of about 1.2% μm −1 or lower, whereas moderate morphology and structural quality could be achieved for a mismatch grading rate up to 2.4% μm −1 . A thin GSMBE grown linear graded InAlAs buffer layer of 1.4 μm is sufficient to relax the strain of an InGaAs layer with 1.7% mismatch to the InP substrate and reach a good quality of the wafer. The relaxation mechanisms of the buffer at different grading rates were also discussed.

Effect of proton irradiation on extended wavelength In0.83Ga0.17As infrared detector

“…The material samples M1 and M2 with InAlAs /In 0.83 Ga 0.17 As/InAlAs p-i-n epitaxial structure were grown on semi-insulating InP substrate by Gas Source Molecular Beam Epitaxy (GSMBE) [14,17]. The epitaxial structure consisted of a 1.9 lm N-InAlAs buffer layer with a doping concentration of about 3 Â 10 18 cm À3 , a 1.5 lm n-In 0.83 Ga 0.17 As absorption layer (3 Â 10 16 cm À3 ) and a 0.6 lm P-InAlAs cap layer (2 Â 10 18 cm À3 ).…”

“…The irradiation inducing degeneration of the performances of lattice-matched InGaAs detector has been studied in detail by http many researchers [7][8][9][10][11]. Extended wavelength InGaAs detectors attracted much attention in recent decades [2,[12][13][14][15]. However, the investigations on their irradiation effect are still far from enough.…”

Temperature dependence of Ohmic contacts of In0.83Ga0.17As photodiodes and its correlation with interface microstructure

“…The extended wavelength InGaAs detector can cover 1.0-2.5 lm detection waveband with 0.83 indium content, and it has several advantages such as high responsivity, wonderful uniformity and low energy consumption, so it can be widely used in space remote sensing, passive night vision and so on [1][2][3][4][5][6][7][8]. It is a well-known fact that the research of Ohmic contacts is a fundamental topic for semiconductors, and Ohmic contact is very important for semiconductor detector [9][10][11][12][13], because it affects the quantum efficiency and response time, and generally, the Ohmic contact resistance is the-smaller-the-better.…”

Effect of buffer layer annealing temperature on the crystalline quality of In0.82Ga0.18As layers grown by two-step growth method

“…In recent years, there are growing needs for photodetectors covering the short wave infrared (SWIR) band (up to 2.5 m), the most important applications are spectral imaging including earth observation [1], remote sensing and environmental monitoring, other applications are gas detection, spectroscopy, and night vision [2][3][4]. Compared with HgCdTe or antimonide materials, the ternary InGaAs material is a good competitor to cover this band [5,6].…”