THE MAGNETIC-FIELD DEPENDENCE OF R(0)A PRODUCTS IN N-ON-P HOMOJUNCTIONS AND P-ON-N HETEROJUNCTIANS FROM HG0.78CD0.22TE LIQUID-PHASE EPITAXYFILMS

The analysis of R(0)A products as a function of magnetic field in n-on -p diodes using a simple diffusion current model has previously been s hown to yield both J(ep)/J(total) ratio (the relative contribution of the p-side diffusion current) and mu(ep) (the minority carrier, electr on mobility). In this paper, we report the good agreement between the experimental and theoretical dependence of mu(ep) on the hole concentr ation over a wide range between 1 x 10(16) and 4 x 10(17) cm(-3) in n- on-p homojunction diodes fabricated on undoped p-type Hg0.78Cd0.22Te l iquid phase epitaxial (LPE) films. The averaged Jep/Jtotal ratio varie d between 68 and 90% with the hole concentration. These Jep/Jtotal rat ios indicate that other leakage current mechanisms than the p-side dif fusion current were not negligible. Also, for the first time, comparat ive measurements were made on the p(+)n heterojunction diodes consisti ng of As-doped Hg0.70Cd0.30Te and In-doped Hg0.78Cd0.22Te LPE layers. Unlike a typical change in R(0)A products by a factor of 2-3 in n-on-p homojunction diodes, the R(0)A products in p(+)/n heterojunction diod es at 7 kG were typically only 2-3% higher than that at the zero field . The typical Jep/Jtotal ratio in p(+)/n heterojunction diodes was abo ut 3-4%, which confirms the general belief that the p(+) cap layer, du e to the high doping and a larger bandgap, contributes very little to the total leakage current.