Detection wavelength of InGaAs/AlGaAs quantum wells and superlattices

Abstract

InGaAs/AlGaAs quantum well structures have been shown to be versatile for infrared detection. By changing the material composition, one can tune the detection wavelength from 2 to 35 μm and beyond. However, there have been few systematic calculations on the absorption wavelength of these structures with respect to their structural parameters. In this work we have adopted the transfer-matrix method to calculate both their energy levels and the wave functions. From this calculation, the absorption and the responsivity spectra of the structures can be predicted. The theory agrees with the experimental result of the test structures. Supported by the experimental evidence, we applied the calculation to a general class of midwavelength detectors and thus established a useful guideline for the detector design in this wavelength range.

Multi-band and broad-band infrared detectors based on III–V materials for spectral imaging instruments

“…Typically in QWIPs, the dark current is dominated by thermal excitation across the sub-band gap, which sets the operating temperature [1][2][3][4][5][6]. During the design, the longest wavelength QWIP device structure (D4) was optimized to minimize the dark current.…”

“…In addition, multi-quantum well (MQW) parameters of the GaAs/Al x Ga 1Àx As based QWIPs can be varied over a range wide enough to enable light detection at any wavelength range from 6 to 25 lm [1,2]. By adding a few monolayers of In y Ga 1Ày As during the GaAs quantum well growth, the short wavelength limit can be extended to 3 lm [6]. The spectral bandwidth of these detectors can be tuned from narrow (Dk/k $ 10%) to wide (Dk/k $ 40%), according to application requirements [7].…”

Characterization of corrugated MQW heterostructure prepared on patterned (001) GaAs substrate by MOVPE

“…As the result, the incorporation of an optical coupler is necessary to couple the intersubband transition to normal incidence light for infrared absorption. [3] Among the existing coupling approaches, the use of a corrugation in C-QWIPs has been demonstrated to be simple and efficient for the coupling [4,5]. In this technique, corrugation lines were etched off in the planar MQW heterostructure.…”

Design and fabrication of resonator-quantum well infrared photodetector for SF6 gas sensor application

“…The material is designed to detect at a peak wavelength λ peak of 10.6 μm with a 1-μm bandwidth. The absorption coefficient (α) of the material with different N D is calculated from the standard transfer matrix method 15,16 and is shown in Fig. 2(a).…”