We report on the fabrication of GaAs based p–i–n solar cells containing 5 and 10 layers of type II GaSb quantum rings grown by molecular beam epitaxy. Solar cells containing quantum rings show improved efficiency at longer wavelengths into the near-IR extending up to 1500 nm and show enhanced short-circuit current under 1 sun illumination compared to a GaAs control cell. A reduction in the open-circuit voltage is observed due to the build-up of internal strain. The MBE growth, formation and photoluminescence of single and stacked layers of GaSb/GaAs quantum rings are also presented.

Background/Aim: To assess the correlation between serum HBsAg titers and hepatitis B virus (HBV) DNA levels in patients with hepatitis B envelop antigen‐negative (HBeAg −ve) HBV genotype‐D (HBV/D) infection. Patients and Methods: A total of 106 treatment‐ naïve, HBeAg −ve HBV/D patients were included; 78 in the inactive carrier (IC) state and 28 in the active hepatitis (AH) stage.

The effects of rapid thermal annealing on the photoluminescence emission obtained from ten-layer stacks of GaSb/GaAs type-II single monolayer quantum dots and Stranski–Krastanow grown quantum rings have been studied and interpreted. Post-growth rapid thermal annealing was performed with proximity capping at temperatures from 550 °C to 800 °C, resulting in an increase in photoluminescence emission intensity and a blue shift in peak energy in both types of stacks, together with changes in the activation energy for thermal quenching.