Intensity Of Photoluminescence Signal Research Articles

Fast microwave synthesis and white luminescent emission from Pb1–2xCaxSrxMoO4 (x=0; 0.3; and 0.5) particles

Scheelite with ABO4 structure has been increasingly highlighted in the optoelectronic field. In this study, PbMoO4, Pb0.4Ca0.3Sr0.3MoO4, and Ca0.5Sr0.5MoO4 particles were fast synthesized via microwave-assisted hydrothermal method for 1, 2, 4, and 8 min. The particles were characterized by X-ray diffraction (XRD) and Rietveld refinement, ultraviolet-visible (UV–vis) absorption spectroscopy, photoluminescence (PL), and field emission scanning electron microscopy (FE-SEM). The diffractogram showed a scheelite-type tetragonal structure and a unit cell with space group I41/a, as well as the presence of defects with an increase in the synthesis time in PbMoO4 and Pb0.4Ca0.3Sr0.3MoO4 samples. Rietveld refinement data possibilities the evaluation of distortions in the tetrahedral [MoO4] clusters and FE-SEM images showed octahedral, spherical particles, and flower-like morphology due to the additions of calcium and strontium in the structure. The bandgap of the materials varied between 3.32 and 4.18 eV, which was affected by the increase in the presence of dopants in the materials. The photoluminescence presented by the PL emission spectral showed a typical emission peak in green with the PL signal intensity decreasing with the synthesis time increase for the PCSMO samples, and the longer the synthesis time, the higher the PL signal for CSMO samples. CCT coordinates have been calculated for all samples and its value exhibited that, overall emission is near white light. This parameter infers that Pb0.4Ca0.3Sr0.3MoO4 sample, synthesized in 1 min, may have potential application in commercial LEDs, due to near white emission and fast microwave synthesis.

Scintillation properties of composite films based on CsPbBr3 nanocrystals embedded in PMMA

Transparent composite films of polymethylmethacrylate with embedded CsPbBr3 colloidal nanocrystals (CsPbBr3-PMMA) were obtained. The optical, photoluminescent, and scintillation properties of the composite films were studied. The CsPbBr3-PMMA films had an intense photoluminescence signal and a nanosecond-range photoluminescence decay time (2 ns). The scintillation characteristics of CsPbBr3-PMMA films of different thicknesses were studied upon excitation by α-radiation of radionuclides 239Pu (Eα = 5.15 MeV) and 238Pu (Eα = 5.46 MeV). The sensitivity and minimum detectable activity of the composite films were calculated from the pulse-height spectra. The estimation of the absolute light yield according to the IEC 62372:2021 standard (determining the intrinsic resolution of scintillator) and calculation of the light collection coefficient showed that the 200-μm thick composite film emitted about 860 photons per 1 MeV of absorbed energy. Under α-excitation, the films revealed a fast scintillation response with average decay time of about 1.4 ns.

Creation and repair of luminescence defects in hexagonal boron nitride by irradiation and annealing for optical neutron detection

Hexagonal boron nitride (hBN) is promising for applications in neutron detection and quantum sensing. Here we created spin-dependent luminescence defects in hBN using 50 keV helium ion beam. The irradiated hBN flakes with a dose around 2 × 1014–1 × 1015/cm2 have the maximum photoluminescence (PL) intensity. The PL spectra are in the range of 700–1000 nm with a peak around 818 nm at 297 K after irradiation with a dose of less than 2 × 1014/cm2, which can be eliminated by high temperature annealing at 1097 K due to defects repair according to Raman spectra. However, the PL peaks exhibit a redshift from 818 nm to 830 nm when the irradiation dose is no less than 1 × 1015/cm2. Combining with constrained density functional theory calculations, it is found that high dose irradiation can cause local lattice swelling and further induce the redshift of PL spectra by 12 nm/0.33% strain. Furthermore, we proposal a novel optical neutron detection method by recording the intensity and position of PL signal of luminescence defects induced by neutron-10B nuclear reaction daughter particles. This work would be helpful to create luminescence defects in hBN for quantum sensing, and develop a novel neutron detector.

Low‐Temperature Photoluminescence Investigation of Light‐Induced Degradation in Boron‐Doped CZ Silicon

Light‐induced degradation (LID) in boron‐doped Czochralski grown (CZ) silicon is a severe problem for silicon devices such as solar cells or radiation detectors. Herein, boron‐doped CZ silicon is investigated by low‐temperature photoluminescence (LTPL) spectroscopy. An LID‐related photoluminescence peak is already found while analyzing indium‐doped p‐type silicon samples and is associated with the ASi–Sii defect model. Herein, it is investigated whether a similar peak is present in the spectra of boron‐doped p‐type CZ silicon samples. The presence of change in the photoluminescence signal intensity due to activation of the boron defect is investigated as well. Numerous measurements on boron‐doped samples are made. For this purpose, samples with four different boron doping concentrations are analyzed. The treatments for activation of the boron defect are based on the LID cycle. During an LID cycle, an additional peak or shoulder neither in the areas of the boron‐bound exciton transverse acoustic and nonphonon‐assisted peaks (BTA, BNP) nor in the area of the boron‐bound exciton transverse optical phonon‐assisted peak (BTO) is found. The defect formation also does not lead to a lower photoluminescence (PL) intensity ratio BTO(BE)/ITO(FE).

A dual-mode immunosensing strategy for prostate specific antigen detection: Integration of resonance Raman scattering and photoluminescence properties of ZnS:Mn2+ nanoprobes

Luminescence-based methods are widely used for the detection of prostate specific antigen (PSA), for example during the diagnosis of prostate cancer. However, the accuracy of these methods is sub-optimal. The aim of this study was to develop an accurate and sensitive dual-mode immunosensing technique using a combination of resonance Raman scattering (RRS) and photoluminescence (PL) signals for the detection of PSA. A ZnS:Mn2+ nanoprobe was used as the signal reporter, which exhibits both multi-phonon RRS and PL properties. The RRS signal intensity at 348 cm−1 and the PL signal intensity at 590 nm were used for the quantitative assay of PSA. The reproducibility, selectivity and specificity of this dual-mode immunosensing strategy demonstrated an improvement compared with commercial PSA ELISA kits in the analysis of serum samples. Therefore, the RRS-PL immunosensing technique developed in this study shows potential as a reliable technique to be used in the clinical diagnosis of prostate cancer.

Photoluminescence of n-InP (100) surface passivated with aqueous Na2S solution

Passivation of the n-InP(100) surface with an aqueous solution of sodium sulphide (Na2S) has been investigated by spectroscopic photoluminescence (PL). After sulphide treatment the PL signal intensity of InP increased significantly and this increase is dependent on duration of sulphide passivation. The correlation of the increase in the PL intensity after sulphide treatment with the variation of the solution pH in contact with InP(100) surface has been established, that expect the possibility for optimization of the passivation process by monitoring the change of the solution pH value in the course of sulphide treatment of the semiconductor.

Influence of chromium incorporation on optoelectronic and magnetic properties of Zn1−xCrxS nanocrystals

A series of Zn1−xCrxS powder with (x = 0–0.18) has been obtained by hydrothermal synthesis. Hexagonal phase nanocrystalline structure of powder samples has been emphasized by X-ray diffraction (XRD) showing particle size ranging from ~ 7 to 11 nm. FE-SEM confirms the nanostructure nature of samples. Elemental compositional analysis confirmed the accurate atomic percentage of existing elements using EDX technique. FTIR spectra of Zn1−xCrxS powder samples indicate different bands corresponding to their structure. The fundamental optical bandgap transition observed at 3.36 eV and additional transitions exist for Cr-doped ZnS samples. Photoluminescence (PL) emission spectra of Zn0.82Cr0.18S nanoparticle powder pumped with different excitation wavelengths (200–290 nm) showed different emission peaks, the highest intensity peak at 398 nm is due to fundamental transition of bandgap which agree with the optical results. The sample with x = 0.11 displays the most intense PL signal. Diamagnetic behavior was observed for ZnS compound whereas ferromagnetic behavior was observed for ZnS-doped with Cr.

Enhancement of the quantum dot photoluminescence using transfer-printed porous silicon microcavities

Enhancement of the photoluminescence signal intensity from organic and inorganic fluorophores increases the sensitivity of operation of optical sensors, detectors, and photonic diagnostic assays. Here, we have engineered and compared optical and fluorescence-enhancing properties of two types of one-dimensional porous silicon photonic crystals: a transfer-printed microcavity based on the freestanding photonic crystal and a conventional “one-piece” microcavity created on a monocrystalline silicon substrate. Comparative analysis of the eigenmodes and the photonic bandgaps of both types of microcavities demonstrated a high quality of transfer-printed microcavities and good correlation of their reflection spectra with the spectra of “one-piece” microcavities. Moreover, embedding of a highly concentrated solution of quantum dots (QDs) in the eigenmode localization region of transfer-printed microcavity was followed by three-fold reduction of the full-width-at-half-maximum of their luminescence spectrum at the microcavity eigenmode wavelength, thus confirming a weak coupling regime of QD exciton and microcavity eigenmode interaction and significant enhancement of QD luminescence within the microcavity.

Photoluminescence, Photoacoustic and Structural Characteristics of Polycrystalline Zn2TiO4: Ni2+ Semiconductor

This work presents the investigation, at room temperature, of Zn2TiO4samples containing Ni2+ ions as substitutional impurities. Samples with molecular formula Zn2(1-x)Ni2xTiO4, where x = 0.00, 0.0007, 0.001, 0.0013, 0.002 and 0.003, in which Zn2+ ions were replaced by Ni2+ ions, were prepared through solid-state method, crystalline data were obtained by X-ray diffraction, the elemental composition was determined by X-ray fluorescence and the optical properties were investigated through photoluminescence and photoacoustic techniques. The photoluminescence spectra showed broadbands from 640 nm to 800 nm. The emission of the Zn2(1-x)Ni2xTiO4 samples was assigned to the overlapping of the Ni2+and the Zn2TiO4 emission. The most intense photoluminescence signal was obtained with excitation radiation at a wavelength of 360 nm for the sample with x = 0.001. The photoacoustic spectra showed absorption bands characteristic of semiconductor materials due to the host Zn2TiO4. The energy bandgap of the Zn2(1-x)Ni2xTiO4was obtained from photoacoustic absorption spectra.

Ordered Arrays of Ge(Si) Quantum Dots Incorporated into Two-Dimensional Photonic Crystals

Two different approaches to the integration of self-assembled Ge(Si) quantum dots into two-dimensional photonic crystals are considered. One approach includes the synthesis of an ordered array of Ge(Si) quantum dots on the textured surface of a substrate followed by the formation of a photonic crystal on this array. In the other approach, the photonic crystal itself serves as a template for the ordered growth of quantum dots. It is shown that, by varying the diameter of holes of photonic crystals in the second approach, it is possible to implement the growth of quantum dots in two modes, in which quantum dots are formed inside or outside the holes of the photonic crystal. For structures with ordered quantum dots incorporated into a photonic crystal, an increase in the photoluminescence signal intensity is detected at room temperature in the spectral range 0.9–1.2 eV. This increase is attributed to the interaction of emission from the structure with radiation modes of the photonic crystal.

Structural and optical characterization of GaSb on Si (001) grown by Molecular Beam Epitaxy

GaSb epilayers were grown on Si (001) using molecular beam epitaxy via AlSb quantum dots as an interfacial misfit (IMF) array between the Si substrates and GaSb epilayers. The effect of IMF array thickness, growth temperature and post annealing on the surface morphology, structural and optical properties of the GaSb on Si were investigated. Among five different IMF array thicknesses (5, 10, 20, 40 and 80 ML) that were used in this study, the best result was obtained from the sample with a 20 ML AlSb IMF array. Additionally, it was found that although the full width at half maximum (FWHM) and threading dislocation (TD) densities obtained from high resolution x-ray diffraction curves can be improved by increasing the growth temperature, a decrease in the photoluminescence (PL) signal and an increase in the surface roughness (RMS) emerged. On the other hand, the results indicate that by applying post annealing the GaSb epilayer crystal quality can be improved in terms of FWHM, TD density, PL signal or RMS depending on the post annealing temperature. By applying post annealing at 570 °C for 30 min we achieve a FWHM value of 260 arcsec for a 1 μm thick GaSb epilayer on Si (001) and improve the PL signal intensity without worsening the RMS value.

Enhancement of physical properties of stain-etched porous silicon by integration of WO3 nanoparticles

In this work, we report on the passivation of porous silicon (PS) by tungsten trioxide (WO3) nanostructured thin films deposited via dip-coating of PS in tungsten hexachloride and water/ethanol solution. Structural analysis by Fourier transform infrared spectroscopy showed a partial disappearance of SiHx and SiOSi peaks after WO3 thin film deposition on the PS due to the replacement of H atoms by WO3. Additionally, PS/WO3 sample revealed weakly intense peaks which can be ascribed to OWO and WO bridging bonds. Morphological analysis by atomic force spectroscopy showed the coverage of the PS surface by a nanostructured thin film of dense WO3 nanoparticles with a size ranging from 40 to 60nm. The photoluminescence signal intensity of PS/WO3 samples presents a continuous increase as a function of the immersion time in the precursor solution. This is attributed to a better decoration of the PS surface by WO3 nanoplatelets and a decrease of surface recombination velocity (200×102cm/s for untreated silicon, 137×102cm/s for PS and 99×102cm/s for PS/WO3samples). Hence, a ~50% improvement in the effective lifetime of minority carriers is obtained. Moreover, the deposited WO3 contributed not only to the passivation of PS, but acted as an antireflection layer which enhanced the optical properties of PS by reducing the reflection of light. These obtained results confirmed the benefits of using WO3 thin film as passivation/antireflection coating for possible solar cell application.

Manipulation and Quantification of Graphene Oxide Flake Size: Photoluminescence and Cytotoxicity.

Single-layered graphene oxide (GO) has exhibited great promise in the areas of sensing, membrane filtration, supercapacitors, bioimaging, and therapeutic carriers because of its biocompatibility, large surface area, and electrochemical, photoluminescent, and optical properties. To elucidate how the physical dimensions of GO affect its intrinsic properties, we employed sonication to produce more than 130 different sizes of GO in aqueous dispersion and implemented new approaches to characterize various GO properties as a function of the average flake size. New protocols were developed to determine and compare the flake size of GO dispersions sonicated with energies up to 20 MJ/g by using dynamic light scattering and atomic force microscopy (AFM). The relationship between the average flake size and sonication energy per unit mass of GO was observed to follow a power law. AFM height measurements showed that the sonication of GO yielded monolayered flakes. Photoluminescence of GO was characterized as a function of the sonication energy (or the average flake size which is the monotonic function of the sonication energy), excitation wavelength, and pH of the dispersion. The strong dependence of the photoluminescence intensity on pH control and the variation of the photoluminescence intensity with different flake sizes were observed. An intense photoluminescence signal, likely related to the separation of the oxidative debris from the GO framework, was found at the highest sonication energies (E ≳ 15 MJ/g) or under extremely alkaline conditions (pH ≳ 11). The cytotoxicity of GO was studied with various flake sizes. Size- and concentration-dependent cytotoxicity was observed for cell lines NIH 3T3 and A549. The NIH 3T3 cell line also demonstrated time-dependent cytotoxicity.

Study on the performance of 2.6 µm In0.83Ga0.17As detector with different etch gases

In order to obtain a low-damage recipe in the ICP processing, ICP-induced damage using Cl2/CH4 etch gases in extended wavelength In0.83Ga0.17As detector materials was studied in this paper. The effect of ICP etching on In0.83Ga0.17As samples was characterized qualitatively by the photoluminescence (PL) technology. The etch damage of In0.83Ga0.17As samples was characterized quantitatively by the Transmission Line Model (TLM), current voltage (IV) measurement, signal and noise testing and the Fourier Transform Infrared Spectroscopy (FTIR) technologies. The results showed that the Cl2/CH4 etching processing could lead better detector performance than that Cl2/N2, such as a larger square resistance, a lower dark current, a lower noise voltage and a higher peak detectivity. The lower PL signal intensity and lower dark current could be attributed to the hydrogen decomposed by the CH4 etch gases in the plasma etching process. These hydrogen particles generated non-radiative recombination centers in inner materials to weaken the PL intensity and passivated dangling bond at the surface to reduce the dark current. The larger square resistance resulted from the lower etch damage. The lower dark current meant that the detectors have less dangling bonds and leakage channels.

Nano-XRF Analysis of Metal Impurities Distribution at PL Active Grain Boundaries During mc-Silicon Solar Cell Processing

Metal impurities are known to hinder the performance of commercial Si-based solar cells by inducing bulk recombination, increasing leakage current, and causing direct shunting. Recently, a set of photoluminescence (PL) images of neighboring multicrystalline silicon wafers taken from a cell production line at different processing stages has been acquired. Both band-to-band PL and sub-bandgap PL (subPL) images showed various regions with different PL signal intensity. Interestingly, in several of these regions a reversal of the subPL intensity was observed right after the deposition of the antireflective coating. In this paper, we present the results of the synchrotron-based nano-X-ray fluorescence imaging performed in areas characterized by the subPL reversal to evaluate the possible role of metal decoration in this uncommon behavior. Furthermore, the acquisition of a statistically meaningful set of data for samples taken at different stages of the solar cell manufacturing allows us to shine a light on the precipitation and rediffusion mechanisms of metal impurities at these grain boundaries.

Surface passivation of GaAs nanowires by the atomic layer deposition of AlN

It is shown that the atomic layer deposition of thin AlN layers can be used to passivate the surface states of GaAs nanowires synthesized by molecular-beam epitaxy. Studies of the optical properties of samples by low-temperature photoluminescence measurements shows that the photoluminescence-signal intensity can be increased by a factor of up to five by passivating the nanowires with a 25-A-thick AlN layer.

Effect of Built-in Electric Field on Miniband Structure and Carrier Nonradiative Recombination in InGaAs/GaAsP Superlattice Investigated Using Photoreflectance and Photoluminescence Spectroscopy

Abstract We investigated the effect of built-in electric field on miniband formation and carrier nonradiative recombination in a superlattice structure by using photoreflectance (PR) and photoluminescence (PL) spectroscopy for a strain-balanced InGaAs/GaAsP superlattice inserted in p-i-n GaAs solar cell and n-n GaAs structures. Two critical energies were obtained in the PR spectra, which corresponded to the energy differences between the Γ and π points in the mini-Brillouin zone of the first electron level and the first heavy hole level. The obtained miniband widths of both samples were same, which were smaller than the calculated values by using a flat-band structure model without a built-in electric field. From these results, it was deduced that the built-in electric field does not affect the miniband width. The PL signal intensity of the p-i-n structure samples did not change, whereas that of the n-n structure samples decreased with decreasing barrier thickness. We concluded that the radiative recombination probability decreases and the non-radiative recombination probability increases due to miniband formation.

Fabrication and characterization of ternary Cu8SiS6 and Cu8SiSe6 thin film layers for optoelectronic applications

We have fabricated and characterized Cu8SiS6 and Cu8SiSe6 thin film layers for optoelectronic applications. The layers were fabricated using a two step process by first evaporating a bilayer of Cu/Si on a Mo/glass substrate, followed by an anneal at temperatures in excess of 480°C in a H2S or H2Se containing atmosphere. Different process conditions with different Cu starting layer thickness, different H2S partial pressure and different anneal temperatures and times were evaluated. The best fabricated layers were thin polycrystalline layers with a relatively low amount of secondary phases. Relatively intense photoluminescence signals with a full width at half maximum of about 150meV could be measured on the samples with a peak position of 1.84 and 1.33eV for the Cu8SiS6 and Cu8SiSe6 materials respectively. The absorption coefficient of the Cu8SiS6 layer was determined from absorption and reflection measurements and was larger than 104cm−1 at energies above 1.8eV. Solar cells could not be fabricated so far, because the material appears to be very highly doped, leading to large ohmic leakage behavior in the fabricated solar cell structures.

Low Temperature Fluorinated Silicon FILMS Synthesis

Second-harmonic generation (SHG), photoluminescence (PL) and Fourier-transformed infrared (FT IR) spectra from silicon films with different average size of nanocrystals were analized to develop new possible material for active channel in nonlinear optical devices. Silicon films were prepared with dominant concentrations of silicon bonding with oxygen or fluorine atoms. Also, the volume fraction of nanocrystals was varied from 30% to 70%. It is seen the spectral peak with energy 3.26 eV is related to defects appeared in interface area silicon-silicon dioxide. For films with small silicon crystals (less than 20 nm) the nonlinear optical response contains two spectral peaks. The second peak is caused by optical response from nanocrystal grain boundary that contains oxygen or fluorine atoms incorporated in silicon as dipoles inside film. The optical nonlinear switch device based on the nonlinear optical response of SiOxmedia inside film was proposed. Also, the silicon film with quartz micro-clusters was investigated as material for making the nonlinear optical transmitter device. The structural properties of silicon films can be easily illustrated by using the films morphology which was determined by using atomic-force microscopy. Figure 1 shows the atomic-force microscopic photos for Sample 1, Sample 2 and Sample3, respectively. It is seen, that the nanocrystal grains are in all types of investigated silicon films. The lateral distribution of nanocrystals with dominant orientation (111) are homogeneous for Sample 1 (see Fig. 1 a)), but for the Sample 2 is unhomogeneous due to appeared conglomerates which are created from the amorphous phase separately (see Fig. 1 b)). The Sample 3 has the triangular shape of nanocrystals (111) which are distributed in submicron crystalline (111) domens. It is clear, that there is great difference in morphological properties of three types of films. The HF etching the silicon surface is efficient because at Td=100oC the surface diffusion and desorption from the surface are low. By adding the SiF4 we change the H2 :SiF4 ratio and some amount of fluorine atoms are included into H2SiF6 assembly creation. Because, the etching process is low at [SiF4] =0.25 sccm and [SiF4] =0.375 sccm. After this values of silicon tetra-fluoride flow rate the H2:SiF4 ratio is changed to destruct intensive creation of molecular assemblies. This stage at [SiF4] =0.5 sccm the HF significant etches the silicon and causes the decreasing the grain sizes. It is assumed that there are two possibilities of fluorine removing: the first is hydrogen incorporation with fluorine, and, the second, the H2SiF6 assemble is creation by 300oC. The SHG is forbidden for centrosymmetric crystal such as bulk silicon because the sum dipole moment is zero, but it is possible due to the surface breaking symmetry and quadruple terms contributions. The opposite situation is for nanostructured oxidized (or fluorinated) silicon films for which the surface area of great quantity of nanocrystals is significant, and the breaking of symmetry is permanent and lateral isotropic. The spectral characteristic of optical nonlinear response from the thin silicon film strictly depends on the spectral properties of polarization and susceptibility tensors χ(2) distortion and χ(2) Si-O.F are the nonlinear susceptibilities produced by nonzero dipole moment caused by shape distortion from the spherical shape of nanocrystals and due to the existing of dangling bonds caused by fluorine or oxygen incorporation in grain boundary region, respectively. By these values of densities the dipole moments of such nanoscaled ellipsoidal dipoles covered by surface charges can be estimated as PSiO =0.04 Debye and PSiH =0.015 Debye. Therefore, the concentration of nanocrystals mainly plays a great role in PL and SHG signal intensity of radiation due to their great surface area covered by silicon bonds with contaminants (atoms of O, H, F) in grain boundary but not as a separate nanoscaled dipoles. By increasing the nanocrystal quantity inside the silicon film the ratio S/V grows significant. The size effect in PL from nanocrystalline silicon film can be explained by means of statistical method. We suggested that the ƒ(x) is distribution function of crystallites in their sizes, θ(x) is a quantum efficiency of nanocrystalls. It is supposed, that the large quantity of nanocrystals is Gauss distributed in their sizes. The Nnc-Si value is proportional to the square under the both functions ƒ(x) and θ(x) near the zero values. Accordingly, the quantity of emitted hydrogenized nanocrystals by band-to-band radiative transitions is important to esimate the PL linear optical response. For nanocrystalline silicon films for Pin àSout optical scheme χ(2) xxx component of susceptibility tensor is detected. By using optical scheme Pin àPout SHG spectra contains isotropic and anisotropic component of susceptibility tensor χ(2) zzz, χ(2) zxx,χ(2) xxz , and χ(2) xxx. Figure 1

Si/SiGe Heterointerfaces in One-, Two-, and Three-Dimensional Nanostructures: Their Effect on SiGe Light Emission

The development of a light emitter compatible with Si based complementary metal-oxide- semiconductor (CMOS) circuit technology and fast optical interconnects is important for the new generations of microprocessors and computers. Self-assembled Si/Si1-xGex nanostructures (NSs) with light emission in the important optical communication wavelength range of 1.3 – 1.55 μm are compatible with conventional CMOS processes. However, the predicted and experimentally confirmed long carrier radiative lifetimes in Si and Si/Si1-xGex NSs impede the demonstration of efficient light-emitting devices and lasers. Thus, engineering of Si/Si1-xGex heterostructures with controlled composition and interface abruptness is critical in producing the desired fast and efficient photoluminescence (PL) peaked at around 0.8-0.9 eV. In this paper we assess how the nature of the interfaces between SiGe NSs and Si in heterostructures strongly affects carrier mobility and recombination for physical confinement in one dimension (corresponding to the case of quantum wells), two dimensions (quantum wires), and three dimensions (quantum dots). The interface sharpness is influenced by many factors such as growth conditions, strain, and thermal processing, which in practice can make it difficult to attain the ideal structures required. This is certainly the case for NS confinement in one dimension. However, we demonstrate that axial Si/Ge nanowire (NW) heterojunctions (HJs) with a Si/Ge NW diameter in the range 50 – 120 nm produce a clear PL signal associated with band-to-band electron-hole recombination at the NW HJ that is attributed to a specific interfacial SiGe alloy composition. For three-dimensional confinement, the experiments outlined here show that two quite different Si1-xGex NSs incorporated into a Si0.6Ge0.4 wavy structure exhibit an intense PL signal with a characteristic decay time as much as 1000 times shorter than that observed in conventional Si/SiGe NSs. The experimentally observed non-exponential PL decay in Si/SiGe NSs is explained as being due to variations of the distances separating electrons and holes at the Si/SiGe heterointerface. The results demonstrate that an abrupt Si/SiGe heterointerface reduces the carrier radiative recombination lifetime and increases the PL quantum efficiency making these SiGe NSs promising candidates for applications in CMOS compatible light-emitting devices.