Ammonia detection using optical reflectance from porous silicon formed by metal-assisted chemical etching

Abstract

An impact of morphology on reflectance of porous silicon was investigated. Depending on the metal-assisted chemical etching conditions the macro-micro structures could be formed. The reflectance properties of various porous silicon structures after ammonia adsorption were investigated. It was shown that increasing of ammonia concentration in the measurement chamber leads to an increase of the reflectance. The most sensitive structures for ammonia detection are porous silicon having approximately size of pores -10-15 µm. A fast response of porous silicon on the adsorption of ammonia molecules may be used for development of new sensors.

Metal-assisted chemical etching of Ge surface and its effect on photovoltaic devices

“…MaCE can produce nanostructures having high aspect ratios and surface-to-volume ratios [2,3], because the electrochemical etching of Si, which is of diamond cubic crystal structure, is anisotropic and proceeds selectively along the <100> orientation [4,5], In addition, it is a simple and lowcost method. Therefore, MaCE has been applied to the fabrication of devices for various applications such as solar energy conversion, energy storage, chemical and biological sensing, and thermal energy conversion [6][7][8][9].…”

Porous Silicon-Zinc Oxide Nanocomposites Prepared by Atomic Layer Deposition for Biophotonic Applications

“…It is well known that porous silicon (PSi), due to its high surface-to-volume ratio and superior photoluminescence (PL) properties, is an attractive material for optical (bio)sensing applications [1,2]. However, the instability of PSi properties in solutions due to the degradation process needs to be solved in order to obtain a stable response and repeatable results [3].…”

Nanosilicon-Based Composites for (Bio)sensing Applications: Current Status, Advantages, and Perspectives

“…Nowadays, sensors and biosensors based on nano-Si have been successfully applied to molecules [15], biomolecules [16] and light [17] detection using different responses (PL [18,19], SERS [20], I–V [21], reflectance [22,23], resistance [24], capacitance [25], fluorescence [26]) and material modifications (PSi, SiNWs, SiNPs). Such strong interest in (bio)sensors based on nano-Si can be explained by their enhanced surface to volume ratio, biocompatibility, and low-cost.…”