Activation energy study of electron transport in high performance short wavelengths quantum cascade lasers.
We present a method to study current paths through quantum cascade lasers (QCLs). The temperature dependence of the current is measured at a fixed voltage. At low temperatures we find activation energies that correspond to the energy difference between the injector ground state and the upper laser level. At higher temperatures additional paths with larger activation energies are found. Application of this method to high performance QCLs based on strained InGaAs/InAlAs quantum wells and barriers with different band-offsets allows us to identify individual parasitic current paths through the devices. The results give insight into the transport properties of quantum cascade lasers thus providing a useful tool for device optimization.
Pflügl
Christian
C
School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA. pflugl@seas.harvard.edu
Diehl
Laurent
L
Lyakh
Arkadiy
A
Wang
Qi Jie
QJ
Maulini
Richard
R
Tsekoun
Alexei
A
Patel
C Kumar N
CK
Wang
Xiaojun
X
Capasso
Federico
F
D003198:Computer Simulation; D017076:Computer-Aided Design; D004579:Electron Transport; D004735:Energy Transfer; D004867:Equipment Design; D019544:Equipment Failure Analysis; D054023:Lasers, Semiconductor; D008962:Models, Theoretical; D055096:Optical Devices; D045663:Quantum Dots