The evolution of electroluminescence in Ge quantum-dot diodes with the fold number
Journal
Applied Physics Letters
Journal Volume
85
Journal Issue
25
Pages
6107-6109
Date Issued
2004
Author(s)
Abstract
The electroluminescence of the light-emitting diodes with five-, ten and 30-fold p -type Ge quantum dots grown on n+ Si substrates is studied. The enhanced integral electroluminescence intensity and blueshift of the 30-fold one at high temperature (>200 K) act contrary to those in five- and ten-fold ones. It is attributed to the emission in the higher-fold quantum dots enabled by the injected electrons diffusing the farther at the higher temperature. Transmission electron microscopy shows that the size of the Ge quantum dots and the Si component in them, both increase with increasing the fold number. Due to the strain-induced intermixing at the high-fold quantum dots, those dots hence have large band gap and result in the intensity increment and blueshift at the high temperature. © 2004 American Institute of Physics.
SDGs
Other Subjects
Chemical vapor deposition; Electroluminescence; Energy gap; High temperature effects; Optical communication; Self assembly; Semiconducting aluminum compounds; Semiconducting gallium arsenide; Semiconducting germanium; Semiconducting silicon; Semiconductor quantum dots; Strain; Substrates; Transmission electron microscopy; Ultrahigh vacuum; Growth temperature; Lattice mismatch; Multiple quantum dots (MQD); Quantum confinement; Light emitting diodes
Type
journal article