Silicon-germanium spherical quantum dot infrared photodetectors prepared by the combination of bottom-up and top-down technologies
Journal
Journal of Vacuum Science & Technology B
Journal Volume
22
Journal Issue
1
Pages
109-115
Date Issued
2004
Author(s)
Abstract
By combining a bottom-up, i.e., thermal evaporation method, and the top-down technologies, i.e., molecular beam epitaxy, the spherical SiGe quantum dot infrared photodetectors (QDIP) have been successfully fabricated for the first time. The thermal evaporation method was chosen to synthesize spherical SiGe nanoparticles. They are treated with methanol containing alumina powders in the ultrasonic bath to form a single SiGe dot layer with density about 1.6×1011 cm−2. The QDIP exhibits two response regions, i.e., 1–3.5 and 14–20 μm. The peak responsivity of QDIP is 5.4 mA/W at 2 μm and about 0.6 mA/W at 17 μm at a bias of 200 mV. This QDIP also exhibits photovoltaic response, a short circuit current exists at zero bias. This device is capable of operating up to 240 K with good performance.
SDGs
Other Subjects
Alumina; Electron energy levels; Evaporation; Ionization; Methanol; Molecular beam epitaxy; Reactive ion etching; Semiconducting germanium; Semiconducting silicon; Semiconductor quantum dots; Synthesis (chemical); Transmission electron microscopy; Quantum dot infrared photodetectors (QDIP); Thermal evaporation; Ultrasonic bath; Infrared detectors
Type
journal article