K. Fronc

XPS and XRD study of crystalline 3C-SiC grown by sublimation method

Abstract Preliminary XPS and XRD studies of the 3C-SiC polycrystals (with the grain size of order of 100 μm) grown by the sublimation method were performed. The XRD data proved a dominant 3C-SiC structure accompanied by an admixture of the residual 6H-SiC phase. The main core-level photoelectron spectra were analysed in detail. In particular, the C 1s level spectrum revealed a three peaks structure containing the peak indicative of free carbon as well as the remaining two identified as the carbidic components, centered at E B a =282.3 eV and E B b =283.4 eV. The fact, that the most intensive peak ‘a’ was found especially well resolvable in the acquired spectrum (as not observed in the earlier reports) was linked with a dominance of 3C-SiC phase and a relatively high lattice perfection of the crystals studied. Therefore, it enabled us a reliable identification of the main C 1s line component (peak ‘a’) as related to the C-Si bond in cubic Si 1− x C x crystal with slight deviation from stoichiometry (0.5 x ⪝0.54). On the other hand, the minor carbidic component (peak ‘b’) was ascribed to the C-Si bond in the highly C-saturated cubic Si 1− x C x ( x ≃0.6) compound that is present in the surface region.

Cathodoluminescence study of diluted magnetic semiconductor quantum well/micromagnet hybrid structures

Cathodoluminescence (CL) was studied in hybrid structures consisting of a diluted magnetic semiconductor (DMS) Cd1−xMnxTe (x=0.06 and 0.09) quantum well buried 300 A below the surface on which Fe islands with micrometric dimensions were deposited. The CL at T=10 K collected from areas far away from the Fe island was consistent with the photoluminescence spectra obtained prior to Fe deposition as were the raster scans and spot excited CL spectra taken in nonmagnetized structures close to the Fe islands. After a magnetization at a magnetic field of 3 T, the CL peak related to DMS quantum well (QW) shifts by up to 4 meV to lower energy only when the exciting beam is focused close to edges of an island. The observed shifts are interpreted as due to a fringe field, affecting the DMS QW, of magnetic domains formed in the Fe islands. The experiments prove a feasibility of the concept of usage of the fringe fields to achieve further confinement of excitons in submicron DMS/ferromagnet hybrid structures.

Donor gettering in GaAs by rare‐earth elements

Optical and electrical measurements of GaAs layers grown by liquid phase epitaxy with different amounts of Yb metal (0–1000 ppm) added to the Ga solution are reported. The presence of Yb during growth causes strong suppression of all donor‐related optical transitions due to the effective removal of donors, as judged from Hall effect data. We have not found any appreciable increase of the background acceptor concentration during conductivity conversion from n‐type to p‐type, and thus conclude that dominant donor gettering occurs already in the Ga solution. No Yb3+ (4f 13)‐related emission was detected in the as‐grown GaAs layers.

Resonant spectroscopy of II-VI self-assembled quantum dots: Excited states and exciton-longitudinal optical phonon coupling

Using resonantly excited photoluminescence (PL) along with photoluminescence excitation (PLE) spectroscopies, we study the carrier excitation processes in

Extended-gate field-effect transistor (EG-FET) with molecularly imprinted polymer (MIP) film for selective inosine determination.

\mathrm{CdTe}∕\mathrm{ZnTe}

Magnetic polaron formation and exciton spin relaxation in single Cd1-xMnxTe quantum dots

and

Magnetophotoluminescence study of intershell exchange interaction in CdTe/ZnTe quantum dots

\mathrm{CdSe}∕\mathrm{ZnSe}

Exciton spectroscopy of single CdTe and CdMnTe quantum dots

self-assembled quantum dots (QDs). PLE spectra of single

Molecularly Imprinted Polymer (MIP) Film with Improved Surface Area Developed by Using Metal–Organic Framework (MOF) for Sensitive Lipocalin (NGAL) Determination

\mathrm{CdTe}

Synthesis of ZnAl2O4:(Er3+,Yb3+) spinel-type nanocrystalline upconverting luminescent marker in HeLa carcinoma cells, using a combustion aerosol method route

QDs reflect two major mechanisms for carrier excitation: The first, associated with the presence of sharp and intense lines in the spectrum, is a direct excited-state\char21{}ground-state transition. The second, associated with the appearance of up to four much broader excitation lines, is a longitudinal optical (LO) phonon-assisted absorption directly into the QD ground states. LO phonons with energies of both QDs and