EFFECT OF GROWTH TEMPERATURE ON PHOTOLUMINESCENCE OF INAS GROWN BY ORGANOMETALLIC VAPOR-PHASE EPITAXY

Infrared photoluminescence (PL) from InAs epitaxial layers grown by atmospheric pressure organometallic vapor phase epitaxy (OMVPE) has been studied as a function of the growth temperature (350-600-degrees-C). It is shown that the PL spectra depend strongly on the growth temperature. The integrated PL intensity decreases by about two orders of magnitude as the growth temperature decreases from 500 to 350-degrees-C. In addition, Hall-effect measurements show that the n-type impurity concentration in InAs increases rapidly as the growth temperature decreases. The results of secondary-ion mass spectroscopy show that the dominant impurity is carbon and its concentration varies with the growth temperature in a similar way to the electron concentration. This confirms that carbon is a donor in InAs. The decreasing PL intensity with decreasing growth temperature is attributed to the increasing carbon concentration.