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Publication Citation: High-Resolution Photocurrent Microscopy Using Near-Field Cathodoluminescence of Quantum Dots

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Author(s): Heayoung Yoon; Youngmin Lee; Christopher Bohn; Seung H. Ko; Anthony G. Gianfrancesco; Jonathan S. Steckel; Seth Coe-Sullivan; Albert A. Talin; Nikolai B. Zhitenev;
Title: High-Resolution Photocurrent Microscopy Using Near-Field Cathodoluminescence of Quantum Dots
Published: June 10, 2013
Abstract: We report a fast, versatile photocurrent imaging technique to visualize the local photo response of solar energy devices and optoelectronics using near-field cathodoluminescence (CL) from a homogeneous quantum dot layer. This approach is quantitatively compared with direct measurements of high-resolution Electron Beam Induced Current (EBIC) using a thin film solar cell (n-CdS / p-CdTe). Qualitatively, the observed image contrast is similar, showing strong enhancement of the carrier collection efficiency at the p-n junction and near the grain boundaries. The spatial resolution of the new technique, termed Q-EBIC (EBIC using quantum dot phosphor), is determined by the absorption depth of photons, ≈150 nm in the CdTe solar cell at the wavelength of ≈620 nm. The results demonstrate a new method for high-resolution, sub-wavelength photocurrent imaging measurement relevant for wide range of applications.
Citation: AIP Advances
Volume: 3
Issue: 6
Keywords: electron beam; quantum dot; phosphor; cathodoluminescence; photocurrent; CdTe
Research Areas: Electron microscopy (EM, TEM, SEM, STEM), Nanoparticles, Focused ion beam imaging (FIB), Energy Conversion, Storage, and Transport
DOI: http://dx.doi.org/10.1063/1.4811275  (Note: May link to a non-U.S. Government webpage)
PDF version: PDF Document Click here to retrieve PDF version of paper (2MB)