Temperature-independent Photoluminescence Research Articles

Temperature Effect of Ionic Transition Metal Complex Light-Emitting Electrochemical Cells

ABSTRACTLight-Emitting Electrochemical Cells (LECs) consist of solution processable ionic light-emitting materials and use air stable electrodes. Their operational mechanism relies on both ionic and electronic conduction. The dynamic behavior is primarily determined by the ionic conductivity. Here, we demonstrate that with increasing temperature the LECs turn-on faster yet without decreasing the efficiency. This is due to the activation energy of ionic transport and the temperature independent photoluminescence quantum yields.

Temperature stable 13 μm emission from GaAs

Gallium arsenide has outstanding performance in optical communication devices for light source purposes. Different approaches have been done to realize the luminescence from GaAs matching the transmission window of optical fibers. Here we present the realization of quasi- temperature independent photoluminescence at around 1.3 {\mu}m from millisecond-range thermally treated GaAs. It is shown that the VAs donor and X acceptor pairs are responsible for the 1.3 {\mu}m emission. The influence of the flash-lamp-annealing on the donor-acceptor pair (DAP) formation in the nitrogen and manganese doped and un-doped semi-insulating GaAs wafers were investigated. The concentration of DAP and the 1.3 {\mu}m emission can be easily tuned by controlling doping and annealing conditions.

Temperature-Independent Photoluminescence in Amorphous Si1-xCx: (F, H) Films with Low Defect Density

Photoluminescence and electron spin resonance measurements were carried out on amorphous silicon-carbon alloy film containing both F and H (a-Si1-xCx: (F, H)) prepared by the glow discharge decomposition of a mixture of SiH4 and CF4 gas. The a-Si1-xCx:(F, H) film, which had a wide optical gap (about 2.8 eV) had a smaller spin density and a photoluminescence with a higher intensity at room temperature and with a weaker temperature dependence than the a-Si1-xCx:H film with a similar optical gap. The temperature-independent photoluminescence appears to be due to an increase in the width of the band tail caused by the incorporation of F atoms.