Novel materials and device design by metal-organic chemical vapour deposition for use in IR emitters

The authors have grown AlSb and AlAs_xSb_1-x epitaxial layers by metal-organic chemical vapour deposition (MOCVD) using trimethylamine or ethyldimethylamine alane, triethylantimony and arsine. These layers were successfully doped p- or n-type using diethylzinc or tetraethyltin, respectively. The authors have examined the growth of AlAs_xSb_1-x using temperatures of 500 to 600°C, pressures of 65 to 630 torr, V/III ratios of 1-17, and growth rates of 0.3 to 2.7 μm/hour in a horizontal quartz reactor. The authors have also grown gain-guided, injection lasers using AlAsSb for optical confinement and a strained InAsSb/InAs multiquantum well active region using MOCVD. The semi-metal properties of a p-GaAsSb/n-InAs heterojunction were utilised as a source for injection of electrons into the active region of the laser. In pulsed mode, the laser operated up to 210 K with an emission wavelength of 3.8-3.9 μm. The dependence of active region composition on wavelength was determined. The authors also report on the 2-colour emission of a light-emitting diode with two different active regions to demonstrate multistage operation of these devices