C-atom-induced bandgap modulation in two-dimensional (100) silicon carbon alloys

Abstract

We experimentally studied the effects of the C atom on bandgap E G modulation in two-dimensional (2D) silicon carbon alloys, Si 1%Y C Y , fabricated by hot C + ion implantation into the (100) SOI substrate in a wide range of Y (4 ' 10 %5 : Y : 0.13), in comparison with the characteristics of 3D silicon carbide (SiC). X-ray photoelectron spectroscopy (XPS) and UV-Raman analysis confirm the Si-C, CC , and Si-Si bonds in the 2D-Si 1%Y C Y layer. The photoluminescence (PL) method shows that the E G and PL intensity I PL of 2D-Si 1%Y C Y drastically increase with increasing Y for high Y (;0.005), and thus we demonstrated a high E G of 2.5 eV and a visible wavelength λ PL less than 500 nm. Even for low Y (<10 %3), I PL of 2D-Si 1%Y C Y also increases with increasing Y, owing to the compressive strain of the 2D-Si 1%Y C Y layer caused by the C atoms, but the Y dependence of E G is very small. E G of 2D-Si 1%Y C Y can be controlled by changing Y. Thus, the 2D-Si 1%Y C Y technique is very promising for new E G engineering of future high-performance CMOS and Si photonics.

A Bifunctional Electrolyte Additive for High-Voltage LiNi0.5Mn1.5O4 Positive Electrodes

“…By using the XPS instrument, it is observed that the TMSPO-added electrolyte generates the surface film on the LNMO electrode after the first charging process (Figure ). The binding energies of the observable functional groups in surface films on the LNMO electrode are summarized in Table . ,,,− Figure a–c shows Si 2p XPS spectra, in which any intensities for silicon bonds are negligible. Figure d–f and g–i show C 1s and O 1s XPS spectra, respectively.…”

Nano-SiC region formation in (100) Si-on-insulator substrate: Optimization of hot-C+-ion implantation process to improve photoluminescence intensity

“…18,19) Recently, we have experimentally studied a Si 1−Y C Y layer fabricated by hot-12 C + -ion implantation into a (100) SOI at the substrate temperature T of 900 °C in the wide range of 0.01 < Y ≤ 0.25 and 0.5 ≤ d S ≤ 20 nm. 20,21) The hot-C + -ion implantation process can reduce the ion-implantation-induced damage of the Si layer. 21) As a result, we demonstrated very large bandgaps (E G ≈ 3 eV) and very high PL intensities (I PL ) from the near-UV to visible regions (>400 nm) of the Si 1−Y C Y layer, which markedly increase with increasing Y in Y ≤ 0.25.…”

“…Moreover, the C atom segregation disappeared only at the surface-oxide interface after oxidation for the thinning process of Si layers, since C atoms near the surface-oxide= Si interface are outgassed by CO gas during the oxidation for the thinning SOI layer. 20,21) Very high PL emission, which is about 100 times higher than that from 2D-Si, 21) originates from the C segregation layer at the SOI=BOX interface in a thinned Si 1−Y C Y layer. Thus, the hot-12 C + -ion implantation technique is highly suitable for visible-region Si-based photonic devices.…”

Physical mechanism for photon emissions from group-IV-semiconductor quantum-dots in quartz-glass and thermal-oxide layers

“…Recently, for realizing Si-based photonics, [1][2][3] we have been experimentally studied photon emissions from nano-structures of group-IV semiconductors (Si, SiC, and C), such as two-dimensional (2D) Si, 4,5) SiC-nano-dots in various crystal structures of Si [6][7][8][9][10][11] [amorphous-Si (a-Si), poly-Si, crystal-Si (c-Si)], and group-IV semiconductor quantum-dots (IV-QD) of Si, SiC, and C in thermal Si-oxide (OX). 12,13) Si-, SiC-, and C-dots were fabricated by very simple hot-ion implantations of single Si + , double Si + /C + , and single C + , respectively, and a post N 2 annealing was carried out to improve the dot quality.…”