Keita Asakura

Emission wavelength control of self-catalytic InP/GaInAs/InP core–multishell nanowire on InP substrate grown by metal organic vapor phase epitaxy

InP nanowires and InP/GaInAs/InP core–multishell nanowires were successfully grown on an InP(111)B substrate by low-pressure metal organic vapor phase epitaxy (MOVPE) using an indium catalyst. The self-catalytic vapor–liquid–solid (VLS) mode was used to obtain high-quality nanowires in which a deposited indium droplet acts as the catalyst instead of a metal particle, as in the case of the conventional VLS mode. InP core nanowire structures dependent on growth temperature and preheating temperature were obtained. InP/GaInAs/InP core–multishell nanowire structures, densities, and optical properties were investigated at various flow rates of trimethylindium (TMI) during the growth of InP core nanowires and the growth time of the GaInAs shell layer was also studied. The growth volume and density of nanowires were mainly dependent on growth temperature and preheating temperature, respectively. The height of nanowires was dependent on the TMI flow rate in the InP core nanowire growth, and the thickness of GaInAs shell layer was controlled by adjusting the growth time of the GaInAs shell layer. The photoluminescence (PL) intensity increased with increasing nanowire height and the peak wavelength was controlled by adjusting the thickness of the GaInAs shell layer.

Electrical characteristic of n-InP/ i-GaInAs/ p-InP core-multishell NWs grown by self-catalytic VLS mode

The core-multishell nanowires of n-InP/ i-GaInAs/ p-InP were successfully grown on an InP(111)B substrate by low-pressure metal organic vapor phase epitaxy (MOVPE) using an indium self-catalyst. The self-catalytic vapor-liquid-solid (VLS) mode was used to obtain high-quality nanowires in which a deposited indium droplet acts as the catalyst instead of a metal particle, as in the case of the conventional VLS mode. An n-InP core nanowires were grown by VLS mode, and GaInAs/ InP shells were grown by VPE mode, by supplying trimethylindium (TMI), tertiarybutylphosphine (TBP), triethylgallium (TEG), and tertiarybutylarsenic (TBAs), respectively, and their dopant were ditiarybutylsilicon (DTBSi) and diethylzinc (DEZn). Spin-on-glass and patterned electrodes were formed, and voltage-current characteristics of n-InP/ i-GaInAs/ p-InP core-multishell nanowires have shown typical rectifying characteristics of p-i-n diode, and the ideality factor of this sample was n=3.2.

PL emission of InP/GalnAs/InP core-multishell NWs grown by self-catalytic VLS mode

Photoluminescence emission of InP/GalnAs/InP coremultishell nanowires was obtained at room temperature. InP nanowires were grown on InP(111)B substrate by selfcatalytic VLS mode of MOVPE using an indium catalyst. InP-core and GaInAs-shell structure was grown by changing the growth temperature. We have successfully obtained the PL emission from these core-shell nanowires at room temperature, and measured the PL spectrum dependent on the thickness of GaInAs-shell.