Twinning Superlattice Formation in GaAs Nanowires

Abstract

Semiconductor nanowires have proven a versatile platform for the realization of novel structures unachievable by traditional planar epitaxy techniques. Among these, the periodic arrangement of twin planes to form twinning superlattice structures has generated particular interest. Here we demonstrate twinning superlattice formation in GaAs nanowires and investigate the diameter dependence of both morphology and twin plane spacing. An approximately linear relationship is found between plane spacing and nanowire diameter, which contrasts with previous results reported for both InP and GaP. Through modeling, we relate this to both the higher twin plane surface energy of GaAs coupled with the lower supersaturation relevant to Au seeded GaAs nanowire growth. Understanding and modeling the mechanism of twinning superlattice formation in III-V nanowires not only provides fundamental insight into the growth process, but also opens the door to the possibility of tailoring twin spacing for various electronic and mechanical applications.

Interaction between lamellar twinning and catalyst dynamics in spontaneous core–shell InGaP nanowires

“…First, the core is grown through the catalyst by VLS; conditions are subsequently changed to promote preferential vapor-solid growth and the shell is formed. The nonconcentric core-shell structure obtained can be explained by the difference in growth rates for A and B facets 22 , enhanced by strain-related surface diffusion and mass transport 23 . Such effects can be avoided by growing a spontaneous shell.…”

Doping Effects on Polytypism in Semiconductor Nanowires: A First-Principles Study

“…Recently, periodic arrangements of twin planes such as twin-plane superlattices have been reported for a variety of group III-V semiconductor NW systems such as InAs [7][8][9][10], InP [11][12][13][14], and GaAs NWs [15]. The crystal structure of InP NWs has been now controlled by Zn doping during the vapor-liquid-solid (VLS) growth: the addition of small amounts of Zn to vapor phase results in the growth of NWs with ZB structure [13][14][15][16][17][18]. The growth of InP NWs on InP(111)B substrate has also been successfully controlled by supplying Zn dopants during the selective area growth [19].…”

Dopant‐Free Twinning Superlattice Formation in InSb and InP Nanowires

“…Thus, TSL is a desired structure for thermoelectric applications . Currently, TSL has been reported in many III‐As and III‐P nanowires, which include InAs, InP, GaAs, and GaP nanowires, as well as some Zn containing compound nanowires, such as ZnO, ZnSe, ZnS, ZnTe …”

“…There are two approaches to induce TSL in III‐V nanowires: introducing Zn as dopant during vapor‐liquid‐solid (VLS) growth of the nanowires and controlling the nanowire growth parameters . TSL formation in InP nanowires by Zn doping was first explored by Algra et al With the addition of Zn dopants, the nanowire surface energy becomes a dominant factor in the growth kinetics.…”

“…Introducing Zn during the nanowire growth is commonly used to engineer the effective surface roughness of nanowires, by producing periodic twinning in GaP, InP and GaAs nanowires . However, this is not the only approach for TSL formation, since both In and Sb also have low surface energy and can be used for tuning the surface energy .…”