Direct nanoscale imaging of evolving electric field domains in quantum structures.

ABSTRACT: The external performance of quantum optoelectronic devices is governed by the spatial profiles of electrons and potentials within the active regions of these devices. For example, in quantum cascade lasers (QCLs), the electric field domain (EFD) hypothesis posits that the potential distribution might be simultaneously spatially nonuniform and temporally unstable. Unfortunately, there exists no prior means of probing the inner potential profile directly. Here we report the nanoscale measured electric potential distribution inside operating QCLs by using scanning voltage microscopy at a cryogenic temperature. We prove that, per the EFD hypothesis, the multi-quantum-well active region is indeed divided into multiple sections having distinctly different electric fields. The electric field acro

SUBMITTER: Dhar RS 

PROVIDER: S-EPMC4246203 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature