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The changes of structural and photoluminescence (PL) characteristics of MBE-grown CdZnSe/ZnSe single quantum well (QW) structures caused by Cd/Zn interdiffusion were studied by high-resolution X-ray diffraction (HRXRD) and low-temperature PL methods. The PL investigations showed that the increase of Cd content in the QW resulted in the increase of the depth of potential fluctuations in the QW as well as in the decrease of ZnSe cap layer band gap (up to several meV). The HRXRD scans as well as reciprocal space maps measured for symmetrical and asymmetrical diffractions revealed the formation of CdZnSe layers near the QW/ZnSe interface with Cd content of order of several percents. It is found that in some samples, the Cd profile in these layers is rather smooth while in others it is quite abrupt. In the latter case, the partial strain relaxation can occur in these layers.

A major challenge in high-resolution x-ray free-electron laser-based coherent diffractive imaging is the development of aerosol injectors that can efficiently deliver particles to the peak intensity of the focused X-ray beam. Here, we consider the use of a simple convergent-orifice nozzle for producing tightly focused beams of particles. Through optical imaging we show that 0.5 μm particles can be focused to a full-width at half maximum diameter of 4.2 μm, and we demonstrate the use of such a nozzle for injecting viruses into a micro-focused soft-X-ray FEL beam.

Variations of the characteristics of Sb-surfactant assisted grown InGaAsN/GaAs single quantum wells (QWs) in dependence on QW growth temperature ( T GR = 442–505 °C) are investigated by the photoluminescence (PL) and high-resolution X-ray diffraction (HRXRD) methods. The QWs grown at ∼480 °C demonstrated optimal PL characteristics, namely the highest PL intensity and small potential fluctuations. A good quality of heterointerfaces is proved by HRXRD. These structures emit at ∼1.29 μm at 300 K and are promising for application in long wavelength opto-electronic devices. The good structural properties of these QWs are assigned to Sb surfactant effect that allows shifting of the T GR to higher temperatures without significant alloy decomposition. The increase of T GR in its turn results in the decrease of the density of nonradiative defects that are the specific feature of low temperature growth.