Conductive-probe atomic force microscopy as a characterization tool for nanowire-based solar cells. (November 2017)

• Record Type: Journal Article
• Authors: Mikulik, Dmitry; Ricci, Maria; Tutuncuoglu, Gozde; Matteini, Federico; Vukajlovic, Jelena; Vulic, Natasa; Alarcon-Llado, Esther; Fontcuberta i Morral, Anna
• Is Part Of: Nano energy. Volume 41(2017:Nov.)
• Page Start: 566
• Page End: 572
• Publication Date: 2017-11
• Subjects: Next generation photovoltaics -- Nanowire-based solar cells -- Conductive-AFM -- III–V semiconductors; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2017.10.016
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: The photonic properties of nanowires advocate for their utilization in next generation solar cells. Compared to traditional devices, the electric scheme is transformed from a single into an ensemble of pn junctions connected in parallel. This new configuration requires new schemes for the characterization. We show how conductive-probe atomic force microscopy, C-AFM, is an essential tool for the characterization and optimization of this parallel-connected nanowire devices. With C-AFM it is possible to obtain both surface topography and local electrical characterization with nanoscale resolution. We demonstrate topography and current mapping of nanowire forests, combined with current-voltage measurements of the individual nanowire junctions from the ensemble. Our results provide discussion elements on some factors limiting the performance of a nanowire-based solar cell and thereby to provide a path for their improvement. Graphical abstract: Highlights: Conductive atomic force microscopy is applied to nanowire-based solar cells. The statistical properties of the nanowire pn-junctions is studied. The performance of single nanowire devices is compared to the full device. Non-uniformity of electrical properties in the nanowire ensemble is revealed. A few poor-performing nanowire devices may not be critical for the full device.