Unexpected benefits of stacking faults on the electronic structure and optical emission in wurtzite GaAs/GaInP core/shell nanowires

Publication Type:
Journal Article
Nanoscale, 2019, 11 (18), pp. 9207 - 9215
Issue Date:
Filename Description Size
c9nr01213c.pdfPublished Version3.66 MB
Adobe PDF
Full metadata record
© 2019 The Royal Society of Chemistry. Wurtzite (WZ) GaAs nanowires (NWs) are of considerable interest for novel optoelectronic applications, yet high quality NWs are still under development. Understanding of their polytypic crystal structure and band structure is the key to improving their emission characteristics. In this work we report that the Ga 1-x In x P shell provides ideal passivation on polytypic WZ GaAs NWs, producing high quantum efficiency (up to 80%). From optical measurements, we find that the polytypic nature of the NWs which presents itself as planar defects does not reduce the emission efficiency. A hole transferring approach from the valence band of the zinc blende segments to the light hole (LH) band of the WZ phase is proposed to explain the emission enhancement from the conduction band to LH band. The emission intensity does not correlate to the minority carrier lifetime which is usually used to quantify the optical emission quality. Theoretical calculation predicted type-II band transition in polytypic WZ GaAs NWs is confirmed and presents efficient emission at low temperatures. We further demonstrate the performance of single NW photodetectors with a high photocurrent responsivity up to 65 A W -1 operating over the wavelength range from visible to near infrared.
Please use this identifier to cite or link to this item: