Danylyuk S. Charge transport features in low-dimensional heterostructures based on A3В5 compounds

Complex investigations of charge transfer properties in low-dimensional heterostructures, based on A3В5 compounds have been presented. Al(Ga)As/GaAs quantum wells and systems of self-organizing InAs quantum dots have been investigated. Low-temperature (down to 30 mK) and high magnetic field (up to 10 T) current-voltage and capacitance-voltage measurements as well as photoresponse measurements have been used as main experimental technique. For resonance tunneling diodes a relative contribution to photocurrent from different recombination mechanisms has been considered. Role of photocarriers, directly excited in the quantum well and ones, tunneled from accumulation layer has been clarified. In infrared region of spectrum an importance of contribution from carriers in accumulation layer has been revealed. Investigation of resonant tunneling effect in periodically modulated electrical field created by a system of interlocked finger contacts has been presented. Theoretical model of electric field distribution has been built and verified experimentally. p-i-n diode has been proposed as effective quantum dot spectrometer. Presented method has been used for investigation of electron and hole states of InAs quantum dots in different matrixes. Current bistabilities have been revealed in structures that contain InAs quantum dots. Both Z- and S- shaped behavior has been demonstrated in p-i-n diode with QD and QW in i-region. The effect has been explained by bipolar charge accumulation effects.