Non-resonant tunnelling in short-period superlattices with optical cavities

The vertical transport in short-period InAs/AlSb and GaAs/AlAs superlattices was studied. The negative differential conductivity was observed in a miniband transport regime as a result of the overlapping of confined states in a periodic quantum well structure (Esaki-Tsu mechanism). Several maxima appeared on current–voltage characteristics of the superlattices found in the non-resonant tunnelling regime. They are shown to be due to the influence of the optical cavity on optical transitions within quantum wells (Purcell effect).