Low hole effective mass in thin InAs nanowires

Abstract

The efficiency of nanoscale electronic devices usually is limited by the decrease in the carrier mobilities when the dimensionality is reduced. Using first principles calculations our results reveal that the hole effective masses of InAs nanowires decrease significantly below a threshold diameter. The mobilities have been estimated, and it is shown that for an optimal range of diameters, the hole mobilities exceeds the bulk value by up to five times, whereas the electron mobilities remain comparable to the bulk one. These results indicate that there exists a diameter window where p-type InAs based high-speed nanodevices can be fabricated.

Effects of dangling bonds and diameter on the electronic and optical properties of InAs nanowires

“…The band structure for the wurtzite nanowires by passivation dangling bonds are plotted by dos Santos et al 24 and their results show that for all NWs the VBM and VBM-1 are nondegenerate and have low energy dispersion, so we could see the effect of passivation in band structure. The NWs have one type of dangling bond, shown in Fig.…”

First principles studies of structural, electrical and magnetic properties of semiconductor nanowires

“…For example, the valence charges for pseudo‐H atoms bonded to In (As) atoms should be $ Z = 1.25$ $ (Z = 0.75),$ instead of $ Z = 1.0$ for real H atoms. Figure 8 shows the representative transversal cross‐sections of the NWs studied in 98. Interestingly, in this study it has been shown that the valence band maximum (VBM) is a nondegenerate level with a high energy dispersion, while the level immediately below in energy (VBM‐1) is two‐fold‐degenerate and has a low energy dispersion.…”

“…The results obtained in Ref. 98 suggest that in extremely thin (2–4 nm diameter) InAs NWs, due to quantum confinement and low effective mass hole states, there is a possibility to obtain p‐type conductance with very high mobility.…”

“…The band structure of [111] ZB, [0001] and $[11\bar20]$ WZ InAs NWs with dangling bonds at the surface saturated by pseudo hydrogen atoms have been studied in Ref. 98. Pseudo‐H atoms have fractional valence charges chosen to mimic the changes of bonding in a bulk system.…”

Performance investigations of quantum dot infrared photodetectors

“…These obtained results are compared with experimental results, which are transferred from the voltage coordinates into the electric field intensity coordinates, reported in literatures to show the validity of the proposed model. In our calculations, the drift velocity of electrons within 10 5 À 1.8 Â 10 6 m/s [25] is supposed as the constant 8 Â 10 5 m/s, the parameter m b is chosen as 0.34 m e [26], the other structure parameters from the GaAs or InGaAs QDIP devices [19,20,27,28] are displayed in Table 1 and are adjusted to the same values as those of the QDIP devices used for the experimental verification. Fig.…”