title: Activation energy study of electron transport in high performance short wavelengths quantum cascade lasers.
abstract: 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.
authors.affiliation: School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA. pflugl@seas.harvard.edu
authors.forename: Christian
authors.initials: C
authors.lastname: Pflügl
authors.forename: Laurent
authors.initials: L
authors.lastname: Diehl
authors.forename: Arkadiy
authors.initials: A
authors.lastname: Lyakh
authors.forename: Qi Jie
authors.initials: QJ
authors.lastname: Wang
authors.forename: Richard
authors.initials: R
authors.lastname: Maulini
authors.forename: Alexei
authors.initials: A
authors.lastname: Tsekoun
authors.forename: C Kumar N
authors.initials: CK
authors.lastname: Patel
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Wang
authors.forename: Federico
authors.initials: F
authors.lastname: Capasso
mesh_terms: 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