Tunable Visible and Near-IR Emission from Sub-10 nm Etched Single-Crystal Si Nanopillars

Abstract

Visible and near-IR photoluminescence (PL) is reported from sub-10 nm silicon nanopillars. Pillars were plasma etched from single crystal Si wafers and thinned by utilizing strain-induced, self-terminating oxidation of cylindrical structures. PL, lifetime, and transmission electron microscopy were performed to measure the dimensions and emission characteristics of the pillars. The peak PL energy was found to blue shift with narrowing pillar diameter in accordance with a quantum confinement effect. The blue shift was quantified using a tight binding method simulation that incorporated the strain induced by the thermal oxidation process. These pillars show promise as possible complementary metal oxide semiconductor compatible silicon devices in the form of light-emitting diode or laser structures.

Wet - Chemically Etched Silicon Nanowire Architectures: Formation and Properties

“…Ehbrecht, 1995) and also a lot of publications about PL originating from single SiNWs (e.g. Walavalkar, 2010) or Si-NCs . Basis of most of the PL studies on these low dimensional single structures is mostly a quantum confinement effect, which induces an energy shift of the emission peak with respect of the RT band gap of silicon.…”

Size tunable visible and near-infrared photoluminescence from vertically etched silicon quantum dots

“…By selecting the oxidation temperature as well as the initial dimensions of the convex silicon structure the size of the remaining silicon core can be tuned. 3,11 Samples were fabricated with original mask diameters of 80 and 100 nm and were undercut to produce three uniform corrugations per pillar. The corrugation size was varied between samples.…”

“…Micro-PL was performed in an inverted optical microscope setup with a 457 nm free-space argon ion laser used to pump the sample; the full experimental setup is described in previous work. 3 The data collected from three samples of different preoxidation size is shown in Fig. 3.…”

“…Silicon quantum wells, 1 grown nanowires, 2 etched nanopillars, 3 and quantum dots 4,5 have shown promising electroluminescent and photoluminescent properties. Specifically silicon nanocrystals embedded in a dielectric matrix such as silicon dioxide or silicon nitride have been used as a convenient method to generate complimentary metal on semiconductor ͑CMOS͒ compatible layers of light emitting material.…”

“…3 The samples were etched using a "pseudo-Bosch" recipe using SF 6 and C 4 F 8 to simultaneously etch and passivate, respectively. Under a fixed gas ratio and forward power the etch produces pillars with vertical sidewalls at an etch rate of roughly 250 nm/min; 3 an example of this etch can been seen in frame ͑b͒ of Fig.…”