Nanoscale analysis of electrical junctions in InGaP nanowires grown by template-assisted selective epitaxy

V. Piazza (1) , S. Wirths (2) , N. Bologna (2) , A. Ahmed (1) , F. Bayle (1) , H. Schmid (2) , F. Julien (1) , Maria Tchernycheva (1)

1 C2N (UMR_9001) - Centre de Nanosciences et Nanotechnologies
2 IBM Research [Zurich]

We report the analysis of the electrical properties of In x-1 Ga x P nanowires (NWs) grown by template-assisted selective epitaxy (TASE). The individual NW properties are investigated by means of electron beam induced current microscopy (EBIC) and current-voltage curves acquired on single nano-objects. First, a set of samples containing n-doped InGaP NWs grown on a p-doped Si substrate are investigated. The electrical activity of the hetero-junction between the NWs and the substrate is demonstrated and the material parameters are analyzed, namely the n-doping level is determined in relation with the dopant flow used during the growth. These results were used to design and elaborate InGaP NWs containing a p-n homo-junction. The electrical activity of the homo-junction is evidenced using EBIC mapping on single NWs and material parameters (namely, the doping and the minority carrier diffusion lengths) for the p-and n-doped InGaP segments are estimated. Finally, the first proof of a photovoltaic effect from the NW homo-junctions is obtained by photocurrent measurements of a contacted NW array under white light irradiation.

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Matériaux; Micro et nanotechnologies/Microélectronique

V. Piazza, S. Wirths, N. Bologna, A. Ahmed, F. Bayle, et al.. Nanoscale analysis of electrical junctions in InGaP nanowires grown by template-assisted selective epitaxy. Applied Physics Letters, 2019, 114 (10), pp.103101. ⟨10.1063/1.5085405⟩. ⟨hal-02182870⟩