An atomic force microscope-based investigation of vertical transport through GaAs/GaAlAs/InAlAs/GaAs step-barrier heterostructures

摘要: Study of vertical transport through heterostructures consisting single, double, or multiple quantum barriers is both fundamental and technological interest. While extensive data regarding electron available for single- double-barrier structures, relatively less information step-barrier structures. In this paper, we present results from a study room temperature GaAs/GaAlAs/InAlAs/GaAs multistep-barrier heterostructure. A typical atomic force microscope has been adapted to perform measurements, thus allowing precise control the physical location region measurement. I-V measurements reveal negative differential resistance (NDR) peaks, confirming formation resonant states in triangular well created when voltage bias applied across step barrier. curves have also calculated by numerically solving Schrodinger wave equation structure. Comparison between measured shows reasonable agreement number NDR peaks. However, discrepancies exist values voltages at which these peaks occur. Some possible reasons are discussed work.