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[摘要]：This work studies the Si-doping of GaAs on (631)-oriented substrates as a function of the As-4-beam equivalent pressure (P-As). The electrical properties obtained by Hall effect measurements show that the mobility of the layers grown on (631)-substrates present changes related to carrier compensation processes and the Si-doping changes from p-to n-type when P-As is increased. The optical properties of the samples, as observed by photoluminescence (PL) spectroscopy, modified according to the electrical characteristics. For (631)-samples, when P-As is increased the energy of the maximum intensity PL peak redshifts in the p-type region but, after the threshold of the conduction type conversion, the peak blueshifts in the n-type region. The variation of the PL excitation intensity also shifts the emission energy of the samples as a consequence of the increasing recombination rate for close pairs in donor acceptor pair recombination. Photoluminescence as a function of temperature shows that the activation energy of the PL lines transition is enhanced as P-As is increased. (C) 2012 American Vacuum Society. [DOI:10.1116/1.3687904] |
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