Transient electron transport properties of multiple quantum dots systems
E. Taranko, M. Wiertel, and R. Taranko
The authors present a theoretical study of the transient electron transport in the multiple quantum dots (QDs) systems forced by the suddenly applied bias voltage. The authors argue that a careful inspection of the transient current beat patterns can provide information about the inter-dot hopping amplitudes, quantum dots energy levels and their occupancies before the abrupt change of the bias voltage is made.
J. Appl. Phys. 111, 023711 (2012)
Quantum confinement in Si and Ge nanostructures
E. G. Barbagiovanni, D. J. Lockwood, P. J. Simpson, and L. V. Goncharova
The authors apply perturbative effective mass theory as a broadly applicable theoretical model for quantum confinement (QC) in all Si and Ge nanostructures including quantum wells (QWs), wires (Q-wires), and dots (QDs). Crystalline and amorphous quantum systems were considered separately. The authors found that crystalline materials are best described by a medium confinement model, while amorphous materials exhibit strong confinement regardless of the dimensionality of the system.
J. Appl. Phys. 111, 034307 (2012)
Impact ionization in quantum well infrared photodetectors with different number of periods
Shan Dong, Ning Li, Sihai Chen, Xihui Liu, and Wei Lu
The authors present a detailed investigation of the photocurrent accompanied with impact ionization effect in In0.15Ga0.85As/GaAs multiple quantum well infrared photodetectors (QWIPs) with 10 and 50 periods. The authors observe a remarkable enhancement at high electric field in the sample with 50 periods and a negative differential conductivity in the sample with 10 periods. A theoretical model of the multiplication factor M varying with impact ionization coefficient α, capture probability pc, and well number N is provided to clarify the observed phenomena.
J. Appl. Phys. 111, 034504 (2012)
More Research Highlights
High performance ferroelectric relaxor-PbTiO3 single crystals: Status and perspective
Shujun Zhang and Fei Li
Ferroelectrics are essential components in a wide range of applications, including ultrasonic transducers, sensors, and actuators. In the single crystal form, relaxor-PbTiO3 (PT) piezoelectric materials have been extensively studied due to their ultrahigh piezoelectric and electromechanical properties. In this article, a perspective and future development of relaxor-PT crystals are given.
J. Appl. Phys. 111, 031301 (2012)
