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

Abstract

Corrugated etching techniques were used to fabricate size-tunable silicon quantum dots that luminesce under photoexcitation, tunable over the visible and near infrared. By using the fidelity of lithographic patterning and strain limited, self-terminating oxidation, uniform arrays of pillar containing stacked quantum dots as small as 2 nm were patterned. Furthermore, an array of pillars, with multiple similar sized quantum dots on each pillar, was fabricated and tested. The photoluminescence displayed a multiple, closely peaked emission spectra corresponding to quantum dots with a narrow size distribution. Similar structures can provide quantum confinement effects for future nanophotonic and nanoelectronic devices.

Exciton Dynamics in Semiconductor Nanocrystals

“…For CdS particles that are smaller than 2.4 nm, noticeable blue‐shifts in their optical absorption and PL spectra manifest relative to bulk 91. The same is true for other semiconductor QD systems when they approach sizes smaller than their respective Bohn radii, such as CdSe,92 CdTe,93 ZnS,94 ZnSe,95 and Si 96 . Figure shows the UV‐Vis electronic absorption (left) and PL (right) spectra of differently sized CdTe QDs 97.…”

Wafer-scale nanostructure formation inside vertical nano-pores

“…These nanopillars were fully converted into SiO 2 prior to their embedment in metal and into a suspended membrane. Upon modification of the applied (deep) reactive ion etch settings, the silicon nanopillars can have vertical or sculptured sidewalls [12][13][14], where the latter allows for the formation of quantum dots [13]. While in previous work Si pillars were converted into glass, in our contribution non-sculptured silicon nanopillars in combination conformal deposition steps, corner lithography [15][16] and sacrificial etch steps are applied to realize SiRNbased membranes containing massive arrays of parallel, hollow nanopores with embedded nano-cages.…”

Three-dimensional etching of silicon for the fabrication of low-dimensional and suspended devices

“…1d is included in the ESI. † Combinations of these features can be used to create a variety of interesting structures, which, when combined with a self-terminating oxidation step we have previously reported, 14,15 can have features as small as 2 nm and novel band structures.…”