Cd_1–xMn_xS Diluted Magnetic Semiconductors as Nanostructured Guest Species in Mesoporous Thin‐Film Silica Host Media

Abstract

Recently, we demonstrated the possibility of synthesizing ordered nanowires of diluted magnetic II/VI semiconductors inside the channels of mesoporous silica host structures. Here, we expand this procedure from mesoporous powders to mesoporous thin films. Diluted magnetic semiconductors Cd1–xMnxS were synthesized within the pores of mesoporous thin‐film silica host structures by a wet‐impregnation technique using an aqueous solution of the respective metal acetates, followed by drying steps and a conversion to sulfide by thermal H2S treatment. The presence of Cd1–xMnxS nanoparticles inside the pores was proved by powder X‐ray diffraction, infrared and Raman spectroscopy, and transmission electron microscopy. Photoluminescence excitation measurements clearly demonstrate the quantum size effect of the incorporated nanostructured guest species. The quality of the nanoparticles incorporated into the mesoporous films is comparable to that of those inside the mesoporous powders.

Comparison of the Magnetic and Optical Properties of Wide‐Gap (II,Mn)VI Nanostructures Confined in Mesoporous Silica

“…Similar results were obtained for other host/guest system based syntheses of nanoparticles, like Cd 1-x Mn x Se within MCM-41 silica [68] and Cd 1-x Mn x S within mesoporous thin films. [69] A more detailed discussion on the size dependence of electronic, magnetic and optical properties was given in 2004, when the DMS compound Zn 1-x Mn x S was synthesised inside mesoporous hosts with different pore sizes. [70] For an accurate study three different mesoporous materials, each with cylindrical pores, were used: MCM-41 silica with 3 nm pores and furthermore two SBA-15 silica with 6 and 9 nm pores.…”

(II,Mn)VI nanostructures in mesoporous silica hosts – from powder samples to thin films

“…The synthesis procedures as well as the structural characterization are described in detail for hybrids based on MCM-41 mesoporous SiO 2 hosts in powder form and for those based on SiO 2 MTF structures in Refs. [1] and [3], respectively. The Raman and the photoluminescence (PL) spectroscopic measurements were performed using standard set-ups.…”

“…This tunable pore size yields adjustable sharp upper limits of the guest particle size, allowing one to study the effect of the reduced dimensions on electronic and magnetic properties of the dilute magnetic semiconductors down to the smallest scales of interest. Recently the synthesis procedure was expanded from mesoporous powders to MTFs [2,3] which should increase the technological relevance of these hybrid systems. Here, we demonstrate, first, that the Cd 1-x Mn x S nanostructures within MTF SiO 2 hosts (4 nm pores) and within MCM-41 mesoporous SiO 2 powders (3 nm pores) are comparable and, second, that the properties of the Cd 1-x Mn x S nanostructures are indeed strongly affected by the reduced lateral dimensions.…”

Growth and Properties of ZnMnTe Nanowires

“…A broad range of semiconductor nanowires, also including binary II-VI group materials, have been grown using chemical vapor deposition, thermal evaporation, solvothermal synthesis, and molecular beam epitaxy (MBE) based on the gold-catalyzed vapor-liquid-solid (VLS) mechanism [1]. However, a synthesis of only a few ternary compound semiconductor NWs, such as ZnCdSe [2], CdMnS [3][4][5][6][7], and ZnMnS [7][8][9][10] has been reported so far.…”