Abstract: Under one aspect, a plurality of silicon nanostructures is provided. Each of the silicon nanostructures includes a length and a cross-section, the cross-section being substantially constant along the length, the length being at least 100 microns. Under another aspect, a method of making nanostructures is provided that includes providing a silicon wafer including a thickness and first and second surfaces separated from one another by the thickness; forming a patterned layer of metal on the first surface of the silicon wafer; generating a current through the thickness of the silicon wafer, the metal oxidizing the silicon wafer in a region beneath the patterned layer of the metal; and exposing the silicon wafer to an etchant in the presence of the current, the etchant removing the oxidized region of the silicon wafer so as to define a plurality of nanostructures. Methods of transferring nanowires also are provided.

Abstract: Under one aspect, a structure includes a tetrahedrite substrate; a first contact metal layer disposed over and in direct contact with the tetrahedrite substrate; and a second contact metal layer disposed over the first contact metal layer. A thermoelectric device can include such a structure. Under another aspect, a method includes providing a tetrahedrite substrate; disposing a first contact metal layer over and in direct contact with the tetrahedrite substrate; and disposing a second contact metal layer over the first contact metal layer. A method of making a thermoelectric device can include such a method.

Abstract: Under one aspect, a plurality of silicon nanostructures is provided. Each of the silicon nanostructures includes a length and a cross-section, the cross-section being substantially constant along the length, the length being at least 100 microns. Under another aspect, a method of making nanostructures is provided that includes providing a silicon wafer including a thickness and first and second surfaces separated from one another by the thickness; forming a patterned layer of metal on the first surface of the silicon wafer; generating a current through the thickness of the silicon wafer, the metal oxidizing the silicon wafer in a region beneath the patterned layer of the metal; and exposing the silicon wafer to an etchant in the presence of the current, the etchant removing the oxidized region of the silicon wafer so as to define a plurality of nanostructures. Methods of transferring nanowires also are provided.

Abstract: A multilayer-stacked phase change memory (PCM) device is provided that includes a substrate that is electrically insulative and thermally conductive, a number (n) of PCM layers deposited on the substrate, where each PCM layer is thicker than a previous PCM layer, a number (n?1) layers of passivation layer deposited between the PCM layers, where the (n) PCM layers, and the (n?1) passivation layers form a stacked multi-layer PCM on the substrate, a first electrode deposited on a first side of the multi-layer PCM stack, and a second electrode deposited on a second side of the multi-layer PCM stack, where the first side is opposite the second side, where charge transport is decoupled by stacking the PCM layers with the pasivation layers.