Perpendicular electron transport in GaAs/AlGaAs multiple quantum wells studied by junction space charge techniques
Transient capacitance and admittance spectroscopy techniques have been used to investigate the perpendicular electron transport properties of GaAs/AlGaAs multi-quantum wells. Two transport processes have been studied at weak electric fields: thermionic transport over the barriers and tunnelling processes through the barriers. Purely exponential time dependences have been observed in both cases and the transport rates could therefore be directly measured and compared with theory. The conduction band offset at the GaAs/AlGaAs interface was determined using both measurement techniques and compared with previously published data.