Carrier Separation and Transport in Perovskite Solar Cells Studied by Nanometre-Scale Profiling of Electrical Potential

Journal Article · Mon Sep 28 00:00:00 EDT 2015 · Nature Communications

DOI:https://doi.org/10.1038/ncomms9397· OSTI ID:1225941

Jiang, Chun-Sheng ^[1]; Yang, Mengjin ^[1]; Zhou, Yuanyuan ^[2]; To, Bobby ^[1]; Nanayakkara, Sanjini U. ^[1]; Luther, Joseph M. ^[1]; Zhou, Weilie ^[3]; Berry, Joseph J. ^[1]; van de Lagemaat, Jao ^[1]; Padture, Nitin P. ^[2]; Zhu, Kai ^[1]; Al-Jassim, Mowafak M. ^[1]

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1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
2. Brown Univ., Providence, RI (United States)
3. Univ. of New Orleans, LA (United States)

Organometal–halide perovskite solar cells have greatly improved in just a few years to a power conversion efficiency exceeding 20%. This technology shows unprecedented promise for terawatt-scale deployment of solar energy because of its low-cost, solution-based processing and earth-abundant materials. We have studied charge separation and transport in perovskite solar cells—which are the fundamental mechanisms of device operation and critical factors for power output—by determining the junction structure across the device using the nanoelectrical characterization technique of Kelvin probe force microscopy. Moreover, the distribution of electrical potential across both planar and porous devices demonstrates p–n junction structure at the TiO2/perovskite interfaces and minority-carrier diffusion/drift operation of the devices, rather than the operation mechanism of either an excitonic cell or a p-i-n structure. When we combined the potential profiling results with solar cell performance parameters measured on optimized and thickened devices, we find that carrier mobility is a main factor that needs to be improved for further gains in efficiency of the perovskite solar cells.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
• Grant/Contract Number: AC36-08GO28308; DMR-1305913
• OSTI ID: 1225941
• Report Number(s): NREL/JA-5K00-64457; MainId:19085; UUID:90f0eeff-390a-e511-b3a2-d89d67132a6d; MainAdminId:71963
• Journal Information: Nature Communications, Vol. 6; ISSN 2041-1723
• Publisher: Nature Publishing Group
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
77 NANOSCIENCE AND NANOTECHNOLOGY
charge separation
Kelvin probe force microscopy (KPFM)
perovskite solar cells
solar-photochemistry
transport