Voltage-tunable dual-band InAs quantum-dot infrared photodetectors based on InAs quantum dots with different capping layers

Abstract

A voltage-tunable, dual-band, InAs quantum-dot infrared photodetector (QDIP) is reported. The QDIP consists of InAs quantum dot layers with GaAs and In 0.20 Ga 0.80 As capping layers for extended middle infrared (EMIR, 6-8 µm) and long-wave infrared (LWIR, 8-12 µm) detection, respectively. Voltage-tunable single-and dual-band operations were obtained with good photoresponsivity and photodetectivity selectivity. Since the detection band of the QD FPA can be individually tuned by engineering the capping layers of the InAs QDs, this design approach offers great flexibility in detection for a given spectral region.

Review of current progress in quantum dot infrared photodetectors

“…Fig. 5 shows recently published D£ values as a function of wavelength at 77-80 K. As can be seen, QDIPs [30,31,[42][43][44]47,53,57,66,103,106,[109][110][111][112][113][114][115][116][117][118][119][120][121][122][123][124] have D£ values comparable to those of QWIPs [13,92,102,[125][126][127][128][129]. This is very promising, as D£ values for QDIPs have increased by over two orders of magnitude over last 7-8 years, as seen in Fig.…”

Voltage-Tunable Mid- and Long-Wavelength Dual-Band Infrared Photodetector Based on Hybrid Self-Assembled and Sub-Monolayer Quantum Dots

“…The spectral response of the dual-band QDIP was measured using a Fourier transform infrared spectrometer (FTIR) (Bruker, Leipzig, Germany) at 77 K. Detailed device characterization procedures have been reported [12]. Figure 3 shows the photocurrent spectra of the dual-band QDIP under bias voltages of −3.4 V (blue trace) and +1.6 V (pink trace).…”

“…Quantum-dot infrared photodetector (QDIP) technology has been extensively studied as a promising large area IR sensing and imaging technology due to the advantages provided by the Quantum-dot (QD) nanostructures, including the three-dimensional (3D) quantum confinement that modifies the quantum selection rules to allow surface normal incident light detection [5], low dark current [6], high photoresponsivity [7], and high operating temperature [7,8,9]. QD based MWIR and LWIR dual-band photodetectors have been reported by several research groups [10,11,12] using different techniques including tailoring the sizes of the QDs during the material growth capping the QDs with different capping layers [12], and inserting asymmetric barrier layers [13]. Most of these dual band QDIPs are based on self-assembled QDs grew via the Stranski-Krastanow (S-K) growth mode (referred to as the self-assembled QDs henceforth).…”

Molecular Beam Epitaxy growth and characterization of silicon – Doped InAs dot in a well quantum dot infrared photo detector (DWELL-QDIP)

“…However, due to several limitations imposed by the difficulties in this material there is a continuous search for alternate semiconductor material structures for IR Focal Plane Array (FPA) applications [1]. InAs based dot in a well quantum dot infrared photodetector (DWELL-QDIP) hetero-structure is one among the candidates in addition to type II superlattice structures which promises good control over operating wavelength and temperatures despite the random formation of self assembled quantum dots during growth.…”