Synthesis of metallic, semiconducting, and semi-metallic nanowires through control of InSb growth parameters

Abstract

In this work we present a simple route to grow metallic, semiconducting or semi-metallic nanowires by chemical vapor deposition. Metallic indium (In), semiconducting indium antimonide (InSb) and semi-metallic antimony (Sb) nanowires were successfully synthesized by controlling temperature and hence Sb vapor pressure in the higher eutectic region of the InSb phase diagram. Semiconducting InSb nanowires were synthesized by direct antimonidization of In droplets at a temperature of 480 • C in an Sb-rich environment. I-V measurements on a single 50 nm thick InSb nanowire field-effect transistor show electrons to be the majority carriers with an electron concentration of ≈10 18 cm −3 . Thermally activated Arrhenius conduction was observed in the temperature range from 200-325 K, yielding an activation energy of 0.11 eV. Metallic In nanowires were grown at 600 • C, using a process similar to that for the growth of InSb nanowires. However, the higher growth temperature resulted in Sb re-evaporating from the growing nanowire crystal, leading to growth of In nanowires. The In nanowires were found to have an extremely high (≈10 21 cm −3 ) electron concentration. Temperature dependent conductivity measurements show that at high temperatures the In nanowire conductivity varies as T −3/2 , suggesting that acoustic phonons controlled electron transport. Antimony nanowire growth occurred at 400 • C by a self-catalyzed growth mechanism. Electron transport measurements on a single Sb nanowire reveal p-type conduction, with a hole concentration of ≈10 19 cm −3 . A higher hole mobility compared to electron mobility and the presence of surface states is the most likely cause of the hole-dominated conductivity in the Sb nanowires.

High-quality InSb nanocrystals: synthesis and application in graphene-based near-infrared photodetectors

“…28 The redshi of the Raman peaks results from the phonon connement effect. 29,30 We also measured the absorption spectrum of the InSb NCs, which is shown in Fig. S1 in ESI.…”

“…Besides, the Raman peaks for both of the NCs show a redshi compared with their counterparts of bulk InSb (TO and LO modes locating at 180 and 190 cm À1 , respectively) 28. The redshi of the Raman peaks results from the phonon connement effect 29,30. We also measured the absorption spectrum of the InSb NCs, which is shown in Fig.S1in ESI.…”

Indium Antimonide Nanowires: Synthesis and Properties

“…In the CVD chamber, the surface diffusions play minor role during the growth of NWs so length of the NWs can be easily tunable simply by increasing or decreasing growth time. Thus, to summarize, CVD is a very effective technique which is used for the synthesis of NWs with tuned diameter and length configurations in a wide range [ 22 ] as well as properties of these grown NWs can also be controlled with the help of this technique. A phenomenon of controlled doping can also be carried out with the help of CVD; for intentionally introducing additional doping materials as well as by switching doping precursors, we can generate doping profiles in any direction.…”