Observation of photovoltaic effect within locally doped silicon nanojunctions using conductive probe AFM. (October 2020)

• Record Type: Journal Article
• Authors: Khoury, R.; Alvarez, J.; Ohashi, T.; Martín, I.; Ortega, P.; López, G.; Jin, C.; Li, Z.; Rusli, ; Bulkin, P.; Johnson, E.V.
• Is Part Of: Nano energy. Volume 76(2020)
• Publication Date: 2020-10
• Subjects: Nanojunction -- Photovoltaics -- Self-organization -- Conductive-probe AFM; 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.2020.105072
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Localized p-doped nanojunctions (200–300 nm in diameter) were formed in n-type crystalline silicon substrates and were characterized using scanning electron microscopy (SEM) and conductive-probe atomic force microscopy (C-AFM). Localized doping was performed by diffusion through sub-micron sized holes in a silicon-oxide mask defined using self-organized polystyrene nanoparticles. After oxide removal, a significant brightness contrast in the SEM top and side view images strongly suggested the successful local doping of these areas. Furthermore, local current-voltage measurements performed by C-AFM revealed an open circuit voltage and a short-circuit current only in the areas defined as nanojunctions. This photovoltaic effect is driven by the laser used to control cantilever deflection in the AFM. Graphical abstract: Image 1 Highlights: Self-assembled nanospheres are used to define a mask for nanoscale point contact formation in crystalline silicon. Localized doping is observable in cross-section due to dopant-dependent contrast in secondary electron emission from silicon. I-V curves acquired using a conductive probe AFM show a PV effect within the nanojunctions, excited by the AFM laser.