Manipulating Surface States of III–V Nanowires with Uniaxial Stress

Abstract

III-V compound semiconductors are indispensable materials for today's high-end electronic and optoelectronic devices and are being explored for next-generation transistor logic and quantum technologies. III-V surfaces and interfaces play the leading role in determining device performance, and therefore, methods to control their electronic properties have been developed. Typically, surface passivation studies demonstrated how to limit the density of surface states. Strain has been widely used to improve the electronic transport properties and optoelectronic properties of III-Vs, but the potential of this technology to modify the surface properties still remains to be explored. Here we show that uniaxial stress induces a shift in the energy of the surface states of III-V nanowires, modifying their electronic properties. We demonstrate this phenomenon by modulating the conductivity of InAs nanowires over 4 orders of magnitude with axial strain ranging between -2.5% in compression and 2.1% in tension. The band bending at the surface of the nanostructure is modified from accumulation to depletion reversibly and reproducibly. We provide evidence of this physical effect using a combination of electrical transport measurement, Raman spectroscopy, band-structure modeling, and technology computer aided design (TCAD) simulations. With this methodology, the deformation potentials for the surface states are quantified. These results reveal that strain technology can be used to shift surface states away from energy ranges in which device performance is negatively affected and represent a novel route to engineer the electronic properties of III-V devices.

Heterointerface‐Driven Band Alignment Engineering and its Impact on Macro‐Performance in Semiconductor Multilayer Nanostructures

“…Among all factors, with its inherent determination on actual band alignment, heterointerface is at the heart. It could be effectively regulated by strain, charge, distortion, and defect, which alter macro‐performance and even induce an emergent phenomenon . For instance, in AlGaAs/GaAs heterostructures, nearly impurity‐free interfaces could be formed with a concerted growth sequence, achieving electron mobility as unprecedentedly high as >35 million cm 2 V −1 s −1 .…”

Correlation between Electrical Transport and Nanoscale Strain in InAs/In0.6Ga0.4As Core–Shell Nanowires

“… 7 , 9 , 19 − 21 Previously, considerable piezoresistive and piezoelectric effects in InAs nanowires have been reported. 11 , 22 Surface effects, such as surface-charge accumulation and ionized surface states, have been found to strongly affect the electrical and photonic properties as well as the electromechanical properties of bare InAs nanowires. 23 − 25 The change in the density of accumulated surface charge with strain was considered the main reason for the strong electromechanical response of bare InAs nanowires.…”

An open-source platform to study uniaxial stress effects on nanoscale devices

“…However, a detailed discussion to understand the physical origin of the anomalous piezo-resistance in InAs would exceed the scope of this paper and will be given elsewhere. 56 …”