GaAs₁₋xBix light emitting diodes : a new long wavelength semiconductor light source

GaAs₁₋xBix is an exciting new semiconductor material, which has been pro posed as a new material for infrared light emitting devices. Recent ad vancements in the growth of GaAs₁₋xBix films have made it possible to produce GaAs₁₋xBix light emitting diodes for the first time. Throughout this research we have grown, fabricated and characterized GaAs₁₋xBix light emitting diodes. Similarly structured InxGa₁₋xAs light emitting diodes were also produced and characterized for comparison to the GaAs₁₋xBix devices. Strong electroluminescence was obtained from GaAs₁₋xBix devices, showing two emission peaks, one corresponding to the GaAs₁₋xBix layer and the other to the GaAs cladding. Emission from InxGa₁₋x_As devices was about 100 times brighter than from GaAs₁₋xBix devices. Temperature dependent electroluminescence and photoluminescence measurements of a GaAs₁₋xBix light emitting diode were made and showed some unusual results. The wavelength of the peak in the electroluminescence from the GaAs₁₋xBix was independent of temperature in the range 100 K to 300 K while the GaAs peak shifted with temperature as expected. Photoluminescence measurements on the same structure show temperature dependence of the peak wavelength similar to the temperature dependence of GaAs.Science, Faculty ofPhysics and Astronomy, Department ofGraduat