Directly Linking Low-Angle Grain Boundary Misorientation to Device Functionality for GaAs Grown on Flexible Metal Substrates.

A new growth method to make highly oriented GaAs thin films on flexible metal substrates has been developed, enabling roll-to-roll manufacturing of flexible semiconductor devices. The grains are oriented in the <001> direction with <1° misorientations between them, and they have a comparable mobility to single-crystalline GaAs at high doping concentrations. At the moment, the role of low-angle grain boundaries (LAGBs) on device performance is unknown.

Design and Demonstration of High-Efficiency Quantum Well Solar Cells Employing Thin Strained Superlattices.

Nanostructured quantum well and quantum dot III-V solar cells provide a pathway to implement advanced single-junction photovoltaic device designs that can capture energy typically lost in traditional solar cells. To realize such high-efficiency single-junction devices, nanostructured device designs must be developed that maximize the open circuit voltage by minimizing both non-radiative and radiative components of the diode dark current. In this work, a study of the impact of barrier thickness in strained multiple quantum well solar cell structures suggests that apparent radiative efficiency is suppressed, and the collection efficiency is enhanced, at a quantum well barrier thickness of 4 nm or less.