Interplay between Crystal Structure and Optical Response in Plateau-Rayleigh Zn₂GeO₄/SnO₂ Heterostructures

Hybrid semiconductor nanowire (NW) heterostructures are an ideal playground for cutting-edge optoelectronic nanodevices. Among the several synthesis methods, Plateau-Rayleigh (PR) crystal growth is an effective route for producing decorated NWs with unprecedented properties. However, lateral variations in composition and/or crystal structure are postulated to play a central role in their optical response, but it is difficult to probe correlatively the elemental order, atomic organization, and light emission on length scales of tens to hundreds of nanometers. Usually, electron microscopies are applied to address the formation of clusters and imperfections in representative cross sections of the samples. Herein, a simultaneous spatially resolved nano-analysis of the crystal symmetry, chemical composition, and optical properties of a whole Zn2GeO4/SnO2 NW heterostructure produced by PR instability is provided. The observations show the connection among Zn impurities, secondary phases, and asymmetrically distributed UV emissions present in the crystallites decorating the NW (Zn-doped Sn1-xGexO2). The contributions of the elemental diffusion, crystal domains, and atomic site configurations to the light-emission phenomena are disentangled in these hybrid architectures. The findings elucidate unknown underlying mechanisms that are critical to tailor emergent properties for rationally designing novel complex nanodevices based on 1D materials.