Resonance Tunneling Diode Structures on CdTe Nanowires Made by Conductive AFM

Abstract

Variation of band gap across the nanowire length would be an exceptionally attractive property for the fabrication of on-nanowire devices such as resonance tunneling diodes (RTD). Band gap variation can be achieved by selective thinning of semiconductor wires by scanning probe lithography (SPL) technique. The external bias applied to a conductive AFM tip during scanning of CdTe nanowires was chosen so as to exceed the threshold of electric field-assisted evaporation of CdTe, estimated to be 5.5 V. Relatively high external voltages of 10−11 V cause fast and complete disintegration of a nanowire portion under the tip. In this way the nanowire can be cut to a desired length. Selection of a voltage between 5.5 and 10 V allows one to control the speed of CdTe evaporation. Thus, one can modulate the thickness of the semiconductor with angstrom scale precision along the nanowire length. Smaller diameter of the nanowire results in increase of quantum confinement in selected areas. The double barrier quantum well valence band profile necessary for the manufacturing of RTD Esaki diodes was demonstrated.

Spontaneous Transformation of Stabilizer‐Depleted Binary Semiconductor Nanoparticles into Selenium and Tellurium Nanowires

“…[44] This feature makes sculpting of individual Se NWs by conducting atomic force microscopy (AFM) possible, as was reported for CdTe NWs. [45] Evidently, almost all CdSe NPs were transformed into Se NWs, regardless of the temperature of synthesis (Figs. 1A±C).…”

The Art of SPM: Scanning Probe Microscopy in Materials Science

“…Recent successful manipulation, in particular cutting of individual CNTs, has been reported [132] and theoretically explained. [133,134] Also, Ag [135] and CdTe nanowires [136] were machined using SPM. Finally, controlled moving, turning, and stretching of nanomaterials is possible by applying SPM (Fig.…”

Colloidal synthesis and characterization of CdSe/CdTe core/shell nanowire heterostructures

“…Recently, considerable interest has been attracted to II-VI semiconductor nanomaterials because of their promising optical and electrical properties [1][2][3][4][5]. Colloidal (solution-phase) synthesis is a powerful technique in modern material chemistry, and its ability to precisely control the composition, size and shape of the nanocrystals (NCs) has led to significant advances in nanomaterial synthesis, such as monodispersed nanoparticles (NPs) [6], nanorods (NRs) [7], nanowires (NWs) [8,9] and complicated heterostructures [10][11][12].…”