In this paper, we reported changes in the growth morphology of n+InAs nanowires (NWs) doped with Te which were selectively grown on nano-hole patterned InP(111)B substrates using an MOCVD method. While the vertical growth of InAs NWs in the <111> direction was extremely suppressed, their lateral growth was enhanced when the diethyl-tellurium (DETe) flow rate was increased as they grew. Moreover, the sidewall planes evolved from () (90° against the (111) plane) to a reverse-tapered morphology, which had a 62° slope against the InP (111)B plane, when the Te flow rate and growth time were increased. This indicates that the surfactant effect of adsorbed Te atoms on InAs changes the relative growth rate between (111) and () due to the increase in surface free energy in the growth plane.

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We investigated the effect of phase separation on the Schottky barrier height (SBH) of InAlAs layers grown by metal–organic chemical vapor deposition. The phase separation into the In-rich InAlAs column and Al-rich InAlAs column of In0.52Al0.48As layers was observed when we grew them at a relatively low temperature of below 600 °C. From the photoluminescence spectrum investigation, we found that the band-gap energy decreased from 1.48 eV for a homogeneous In0.52Al0.48As sample to 1.19 eV for a phase-separated InxAl1−xAs sample due to the band-gap lowering effect by In-rich InxAl1−xAs (x > 0.7) region. From the current density–voltage analysis of the InAlAs Schottky diode, it was confirmed that the phase-separated InAlAs layers showed a lower SBH value of about 240 meV than for the normal InAlAs layers. The reduction in SBH arising from the phase separation of InAlAs layers resulted in the larger leakage current in InAlAs Schottky diodes.