Giant photocurrent enhancement by transition metal doping in quantum dot sensitized solar cells

Journal Article · Mon Sep 05 00:00:00 EDT 2016 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4962331· OSTI ID:22594302

Rimal, Gaurab; Pimachev, Artem K.; Yost, Andrew J.; Poudyal, Uma; Maloney, Scott; Wang, Wenyong; Chien, TeYu; Dahnovsky, Yuri; Tang, Jinke ^[1]

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1. Department of Physics and Astronomy, University of Wyoming, Laramie, Wyoming 82071 (United States)

A huge enhancement in the incident photon-to-current efficiency of PbS quantum dot (QD) sensitized solar cells by manganese doping is observed. In the presence of Mn dopants with relatively small concentration (4 at. %), the photoelectric current increases by an average of 300% (up to 700%). This effect cannot be explained by the light absorption mechanism because both the experimental and theoretical absorption spectra demonstrate several times decreases in the absorption coefficient. To explain such dramatic increase in the photocurrent we propose the electron tunneling mechanism from the LUMO of the QD excited state to the Zn{sub 2}SnO{sub 4} (ZTO) semiconductor photoanode. This change is due to the presence of the Mn instead of Pb atom at the QD/ZTO interface. The ab initio calculations confirm this mechanism. This work proposes an alternative route for a significant improvement of the efficiency for quantum dot sensitized solar cells.

• OSTI ID: 22594302
• Journal Information: Applied Physics Letters, Vol. 109, Issue 10; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION
ABSORPTION SPECTRA
DOPED MATERIALS
EFFICIENCY
ELECTRONS
EXCITED STATES
LEAD SULFIDES
MANGANESE
PHOTOANODES
PHOTOCURRENTS
PHOTONS
QUANTUM DOTS
SEMICONDUCTOR MATERIALS
SOLAR CELLS
TIN OXIDES
TUNNEL EFFECT
ZINC OXIDES