DONOR-DOPING EFFECT IN THE GROWTH OF HG1-XCDXTE HETEROLAYERS BY SLIDER LIQUID-PHASE EPITAXY

Donor doping of IIIA elements, including Ga and In, was employed in th e growth of Hg1-xCdxTe (MCT) heterolayers consisting of a wide-bandgap (x = 0.4) layer on the top of a narrow-bandgap one were grown on (111 )B CdTe substrates by liquid phase epitaxy with a Te-rich solution. Th e doping properties of selected impurities in the cap layer (i.e., the wide-bandgap layer) were investigated. The segregation coefficients ( k) of Ga and In were a decreasing function of dopant concentration in the growth solution The diffusion coefficients for In and Ga, determin ed from a fitting of the electron concentration profile in the In-dope d and the Ga-doped n-type cap layers, were in a range of mid 10-(13) t o 10-(12) and similar to 10(-12) cm(2)/s, respectively. An N+-on-p het erojunction mesa diode, consisting of an In-doped n-type epilayer (x = 0.4) on a p-type active layer (x = 0.3), was fabricated. The R(O)A pr oducts at 77 K of the N+-on-p heterojunction was 1.1 X 10(5) Omega . c m(2).