Ambipolar transport in narrow bandgap semiconductor InSb nanowires

Abstract

We report on transport measurement study of top-gated field effect transistors made out of InSb nanowires grown by chemical vapor deposition. The transistors exhibit ambipolar transport characteristics revealed by three distinguished gate-voltage regions: In the middle region where the fermi level resides within the bandgap, the electrical resistance shows an exponential dependence on temperature and gate voltage. With either more positive or negative gate voltages, the devices enter the electron and hole transport regimes, revealed by a resistance decreasing linearly with decreasing temperature. From the transport measurement data of a 1-µm-long device made from a nanowire of 50 nm in diameter, we extract a bandgap energy of 190-220 meV. The off-state current of this device is found to be suppressed within the measurement noise at a temperature of T = 4 K. A shorter, 260-nm-long device is found to exhibit a finite off-state current and a hole, on-state, circumferencenormalized current of 11 µA/µm at VD = 50 mV which is the highest for such a device to our knowledge. The ambipolar transport characteristics make the InSb nanowires attractive for CMOS electronics, hybrid electron-hole quantum systems and hole based spin qubits.

Sulfur-Passivated InSb Nanowires for Infrared Photodetectors

“…35 A more detailed comparison of the data is shown in Table S4. Compared with InSb NWs reported in the literature, the S-InSb NWs prepared in this work have the highest room-temperature mobility and the best infrared photoresponse properties. − These all shape up to be a perfect demonstration of the good optoelectronic properties of our prepared S-InSb NWs.…”

“…The normal distribution of these field-effect mobilities was 365.71 ± 199.19 cm 2 V –1 s –1 , and the maximum value was 823.62 cm 2 V –1 s –1 . As summarized in Table S4, these calculated mobility values were higher than those reported in the literature for InSb NW-based FETs tested at room temperature. − Although the prepared S-InSb NW-based FET devices possess high field-effect mobility, it is far from reaching the highest reported record of 4.4 × 10 4 cm 2 V –1 s –1 , which was tested at a low temperature of 4.2 K . There are two possible reasons for this result: the first being that more phonon scatters are generated, resulting from our room-temperature test in contrast with the low-temperature test in previous reports; , the other being that the field-effect mobility is affected by the surface Sb–S layer of the S-InSb NW. ,, More definitive mechanistic studies are undoubtedly needed in future experiments.…”

“…The photodetector possessed stable NPR performances toward incident infrared light, and the key parameters of responsivity ( R λ ) and external quantum efficiency (EQE) were calculated to be 123.46 A/W and 14,400% for 1.06 μm light, respectively, 59.26 A/W and 5610% for 1.31 μm light, respectively, and 120.99 A/W and 9680% for 1.55 μm light, respectively. Compared with InSb NWs reported in the literature, the S-InSb NWs prepared in this work have the highest room-temperature mobility and superior infrared photoresponse properties. − To reveal the origin of the NPR properties, an analysis of excited electron states in the band structure was performed under light illumination, and the NPR properties were found to stem from the photogating effect of the Sb–S layer on the S-InSb NW surface. ,− …”

Surface band bending caused by native oxides on solution-processed twinned InSb nanowires with p-type conductivity

“…In comparison to other binary/ternary III–V NWs grown via the VLS mechanism, the as-synthesized InSb NWs grown via the solution–liquid–solid (SLS) mechanism without any high temperature equipment and highly reductive atmosphere exhibit very competitive hole mobilities with an n–p switching behavior among all the III–V NW-based FETs. Although the n–p switching behaviors are rare in semiconductor NWs except for VLS-grown InSb, 20 Mn-doped AlN, 43 carbon-doped InSb 18 and GaSb NWs, 44 the as-obtained InSb NWs show the highest hole mobilities without any additional chemical reactions such as element doping. In addition to the intrinsic high carrier mobilities of InSb, we can attribute the good p-type conductivity to the twinned structure with a constant spacing rather than a random distribution, which has been confirmed to lead to the reduced carrier mobilities by increasing carrier and phonon scattering rates.…”

“…The n-type FET devices fabricated with the obtained stemless InSb NWs showed a high electron mobility measured at 4.2 K. 22 Very recently, Dalelkhan et al assembled top-gated NWFETs from InSb NWs generated by CVD on a Si substrate and the resulting NWFETs exhibited good transport characteristics because of the effective regulations. 20…”