Optical Evidence of Charge Accumulation in Double Barrier Diodes

Tunneling is one of the basic quantum mechanical phenomena which plays a key role in many ultra thin semiconductor devices. Besides their potential for applications, double barrier hetero­structures are also interesting for the understanding of tunneling-based transport processes (1) and their dynamics. Time-resolved photoluminescence (PL) has been used to determine the tunneling escape rate of electrons from a single quantum well through a thin barrier into a continuum (2) and to determine the electric field dependance of this tunneling rate (3).The charge accumulation in the quantum well can be estimated using magnetotunneling (4) or as recently demonstrated steady-state photoluminescence (5).