Electrodeposited, Transverse Nanowire Electroluminescent Junctions

Abstract

The preparation by electrodeposition of transverse nanowire electroluminescent junctions (tn-ELJs) is described, and the electroluminescence (EL) properties of these devices are characterized. The lithographically patterned nanowire electrodeposition process is first used to prepare long (millimeters), linear, nanocrystalline CdSe nanowires on glass. The thickness of these nanowires along the emission axis is 60 nm, and the width, wCdSe, along the electrical axis is adjustable from 100 to 450 nm. Ten pairs of nickel-gold electrical contacts are then positioned along the axis of this nanowire using lithographically directed electrodeposition. The resulting linear array of nickel-CdSe-gold junctions produces EL with an external quantum efficiency, EQE, and threshold voltage, Vth, that depend sensitively on wCdSe. EQE increases with increasing electric field and also with increasing wCdSe, and Vth also increases with wCdSe and, therefore, the electrical resistance of the tn-ELJs. Vth down to 1.8(±0.2) V (for wCdSe ≈ 100 nm) and EQE of 5.5(±0.5) × 10(-5) (for wCdSe ≈ 450 nm) are obtained. tn-ELJs produce a broad EL emission envelope, spanning the wavelength range from 600 to 960 nm.

A Study about Schottky Barrier Height and Ideality Factor in Thin Film Transistors with Metal/Zinc Oxide Nanoparticles Structures Aiming Flexible Electronics Application

“…A Schottky barrier appeared in each interface, and electrons faced this energy barrier when one of the diodes was reverse biased. In fact, what limits the current in TFTs is the diode that is reverse biased [ 19 ]. Figure 4 b,c illustrates the case when M D has positive and negative voltages applied, respectively (note that M S is ground potential).…”

“…Figure 4 b,c illustrates the case when M D has positive and negative voltages applied, respectively (note that M S is ground potential). In Figure 4 b, the diode in the M S interface was reverse biased, and the diode in the M D interface was direct biased, and the contrary is presented in Figure 4 c. The equation that regulates the current I(V DS ) in TFTs can thus be written as in [ 19 , 20 ]: where the saturation currents I 1 and I 2 are given by: …”

“…In Figure 4b, the diode in the M S interface was reverse biased, and the diode in the M D interface was direct biased, and the contrary is presented in Figure 4c. The equation that regulates the current I(V DS ) in TFTs can thus be written as in [19,20]:…”

ZnO nanowires and their application in field-effect transistors

“…The complexity of non-Ohmic contacts therefore makes comprehensive modelling of the ZnO nanowires difficult. One model which has been used successfully in the past to model non-Ohmic conduction treats both metal/semiconductor interfaces as Schottky diodes [218,219,220,221,222,223,224]. When metal comes into contact with a semiconductor, a Schottky barrier typically forms at the interface [202].…”

“…While there are several ways of modelling back-to-back Schottky diodes, several of these rely on temperature-dependent measurements. In this chapter, we make use of the current density model first developed by Chiquito et al [218], and later used/adapted by others [219,220,221,222,223,224]. Diode measurements of nanowire devices are taken with no gate voltage applied, and the cross-sectional area of the nanowire is then ascertained using SEM.…”