Two‐ and three‐dimensional composite photonic crystals of macroporous silicon and lead sulfide semiconductor nanostructures

Abstract

We describe a new method for direct deposition and growth of nanocyrstalline lead sulfide (PbS) thin films into two‐ and three‐dimensional arrays of macroporous silicon and the formation of composite silicon photonic crystals (PhCs). Infrared transmission measurements exhibit a substantial red‐shift of the photonic stop bands from the composite PhCs relative to the PhC substrates. Photoluminescence spectroscopy reveals the effect of slow‐light modes on the emission spectra from PbS thin films inside a two‐dimensional PhC. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Composite photonic crystal cavities of macro porous silicon and lead sulfide thin films

“…Next, thin PbS films were locally infiltrated into the host, bare‐PC to create a CPC cavity. We have already reported about the application of the chemical solution deposition technique for depositing thin PbS films over patterned substrates to create a bulk CPC 8–10. Here, the deposition process has been modified as follows.…”

“…The optical properties of PbS have previously been studied by others 6 and recently, also by our group 7. In addition, we have reported recently about the fabrication of composite photonic crystals (CPCs), created by infiltrating PbS thin films into electrochemically etched two‐dimensional (2D) silicon photonic crystals (PCs) 8–10. A key factor in obtaining these high quality CPCs is the infiltration of semiconductor thin films that do not destroy the uniformity of the host silicon‐PCs and the coherency of the emitted light 9, 10.…”

“…1. We discuss the necessary conditions to achieve CPC cavities and provide experimental demonstration for the operation of such a device, which has been fabricated by our infiltration techniques 8–10.…”

Trap and track: designing self-reporting porous Si photonic crystals for rapid bacteria detection

“…Then, anodization is carried out under dark conditions, using an electrolyte solution of HF (49%) and DMF (1 : 7 v/v), at a constant current density (30 mA cm À2 , 125 s). 33,34 The resulting freshly-etched PSi is then chemically oxidized in H 2 O : NH 3 : H 2 O 2 solution in a volumetric ratio of 5 : 1 : 1 at 75 C for 1 h to create a hydrophilic PSiO 2 matrix. Following oxidation, the PSiO 2 samples are chemically modied by silanisation using 2% APTES (diluted in toluene, 1 h), resulting in positively-charged amine groups graed on to the surface.…”

Control of morphology and optical properties of PbS nanostructured thin films by deposition parameters: study of mechanism

“…These inherent properties make PbS one of the most important functional materials used as thin films for several applications such as IR detectors [3], photovoltaic cells [4], thinfilm transistors [5], LEDs [6], gas and biosensors [7][8][9][10][11][12], and photonic crystals [13].…”