Twin-Free GaAs Nanosheets

10 nanolasers and LED applications. 11 GaAs nanostructures (e.g., nanowires and 12 nanosheets) with high surface-to-volume 13 ratios, however, suffer from high surface 14 state densities and high surface recombina15 tion velocities, which typically limit their 16 optoelectronic device performance. Passiva17 tion of GaAs nanostructures has been widely 18 studied in the literature, including cladding of 19 GaAs nanostructures with wide gap materials 20 (e.g., AlGaAs, GaP and GaAsP). 9 A number 21 of chemical routes to passivation of GaAs 22 surfaces have been studied, including sulfur 23 solution passivation, thiol passivation, 24 and ionic liquid passivation. Recently, se25 lective area growth (SAG) of GaAs nano26 sheets has been demonstrated using a slit 27 instead of a hole geometry in the SiN 28 growth masking layer. GaAs nanosheets 29 have the distinct advantage over GaAs nano30 wires in that they grow easily without the 31 formation of twin defects and stacking 32 faults, thus improving the overall sample 33 quality and optoelectronic properties in 34 comparison to GaAs nanowires. Longer 35 minority carrier diffusion lengths make 36 GaAs nanosheets particularly well-suited 37 for solar cell and nanolaser applications.