Engineering of Semiconductor Defects for Nanoscale Devices
Research Overview
Research in this group focuses on the control of defect behavior in semiconducting materials to make nanoscale devices of interest in energy, environmental, and microelectronics applications. Despite the harmful sound of “defect,” such species can actually be beneficial for semiconductor properties. For example, controlled substitution of dopant atoms for host atoms in a semiconductor (as “substitutional defects”) is absolutely essential for the operation of microelectronic devices. Our work aims primarily at controlling the behavior of substitutional, interstitial, and vacancy defects within semiconducting solids and on their surfaces. Indeed, “defect engineering” seeks to control the primary kinds of defects in semiconductors as well as their concentrations, spatial distribution, and mobility. We have discovered several new physical mechanisms to accomplish this control that work particularly well at the nanoscale. The mechanisms include saturation of dangling bonds at a surface and photostimulation. Our work employs both experiments and computations to develop this fundamental science base while simultaneously applying the findings to practical applications.