Printed nanoparticulate composites for silicon thick-film electronics

Abstract

The production of active semiconductor thick-film components typically involves the deposition of precursor materials and subsequent thermal processing to produce a massive semiconductor layer. In this paper, we present electronic materials, based on nanoparticulate silicon, to produce the active semiconducting layer, which can simply be printed onto low-temperature substrates such as paper. Particular emphasis will be given to the structure, morphology, and composition of the nanoparticles, which are produced by either gas-phase decomposition of silane or mechanical attrition of bulk silicon. Of further importance are the electrical characteristics of the composite materials, in which the active semiconductor is formed from an interconnecting backbone of silicon particles. These will be discussed for example structures, including junction field effect transistors (FETs), insulated-gate FETs, and photodiodes.

Size distribution and surface characteristics of silicon nanoparticles

“…Three different types of silicon powders, combined with four different binder materials, were used in the fabrication of the layers studied by SAXS. Two of the powders were produced by high-energy milling from bulk material using an orbital pulverizer (Britton & Hä rting, 2006). Milling was performed in 30 min intervals, with time allowed for the mill to cool between, so that the temperature did not exceed 433 K. The powders were harvested in their dry state directly from the mill.…”

“…In recent years the printing of nanoparticle-based inks as replacements for thin films, coatings and membranes in diverse applications has achieved considerable attention. One particular aspect is the drive towards printable forms of silicon, and other semiconductors, for mass production of large-area devices and circuitry using traditional printing and coating techniques (Britton & Hä rting, 2006).…”

Investigation of surface topology of printed nanoparticle layers using wide-angle low-Qscattering

“…An indication of the surface structure could only be inferred from local information provided by microscopy, as no large-area information could be obtained by scattering. The silicon nanoparticles used in this experiment were obtained from P-type wafers and 2503-grade silicon milled for 5 and 3 h, respectively, using high-energy milling (Britton & Hä rting, 2006). These are referred to as P-Si and M-Si, respectively, and are similar to those used in the production of printed electronics components such as temperature sensors (Mä nnl et al, 2013), field effect transistors (Hä rting et al, 2009) and current switching transistors (Britton et al, 2013).…”

A novel mode of current switching dependent on activated charge transport

“…6,7 n-type and p-type particles were produced by milling highly doped (phosphorous and boron, respectively) single crystalline wafers with an initial resistivity lower than 0.005 cm. Screen printable silicon inks were prepared by addition of silicon powder to an acrylic emulsion ink base (which contains <10% solid fraction), with reagent grade propylene glycol as a thinner, so that the final weight proportions of silicon to binder were 80:20.…”

“…Here we demonstrate a fully printed electronic device with a similar triode configuration, using nanoparticulate silicon as the semiconductor material, 6,7 which has a unique mode of operation as an electrically controlled two-way (double throw) switch. By analogy with the junction transistor and the vacuum tube, we denote the electrodes as emitter, base and collector.…”