Magnetic-field-induced quantum Hall—insulator transition and persistent photoconductivity in InAs/GaAs quantum dot layers

We have investigated the temperature dependence of resistance in the temperature range T=0.07–View the MathML source and in magnetic field up to View the MathML source in InAs/GaAs quantum dot layers. In samples with relatively high carrier concentration quantum Hall effect—insulator transition was observed in high magnetic fields. Two-dimensional Mott variable range hopping conductivity has been observed at low temperatures in samples with low carrier concentration. The length of localization correlates very well with the quantum dot cluster size obtained by atomic force microscope. In all samples a positive persistent photoconductivity was observed.