TY - JOUR
T1 - Facet-dependent photovoltaic efficiency variations in single grains of hybrid halide perovskite
AU - Leblebici, Sibel Y.
AU - Leppert, Linn
AU - Li, Yanbo
AU - Reyes-Lillo, Sebastian E.
AU - Wickenburg, Sebastian
AU - Wong, Ed
AU - Lee, Jiye
AU - Melli, Mauro
AU - Ziegler, Dominik
AU - Angell, Daniel K.
AU - Ogletree, D. Frank
AU - Ashby, Paul D.
AU - Toma, Francesca M.
AU - Neaton, Jeffrey B.
AU - Sharp, Ian D.
AU - Weber-Bargioni, Alexander
PY - 2016/7/4
Y1 - 2016/7/4
N2 - Photovoltaic devices based on hybrid perovskite materials have exceeded 22% efficiency due to high charge-carrier mobilities and lifetimes. Properties such as photocurrent generation and open-circuit voltage are influenced by the microscopic structure and orientation of the perovskite crystals, but are difficult to quantify on the intra-grain length scale and are often treated as homogeneous within the active layer. Here, we map the local short-circuit photocurrent, open-circuit photovoltage, and dark drift current in state-of-the-art methylammonium lead iodide solar cells using photoconductive atomic force microscopy. We find, within individual grains, spatially correlated heterogeneity in short-circuit current and open-circuit voltage up to 0.6 V. These variations are related to different crystal facets and have a direct impact on the macroscopic power conversion efficiency. We attribute this heterogeneity to a facet-dependent density of trap states. These results imply that controlling crystal grain and facet orientation will enable a systematic optimization of polycrystalline and single-crystal devices for photovoltaic and lighting applications.
AB - Photovoltaic devices based on hybrid perovskite materials have exceeded 22% efficiency due to high charge-carrier mobilities and lifetimes. Properties such as photocurrent generation and open-circuit voltage are influenced by the microscopic structure and orientation of the perovskite crystals, but are difficult to quantify on the intra-grain length scale and are often treated as homogeneous within the active layer. Here, we map the local short-circuit photocurrent, open-circuit photovoltage, and dark drift current in state-of-the-art methylammonium lead iodide solar cells using photoconductive atomic force microscopy. We find, within individual grains, spatially correlated heterogeneity in short-circuit current and open-circuit voltage up to 0.6 V. These variations are related to different crystal facets and have a direct impact on the macroscopic power conversion efficiency. We attribute this heterogeneity to a facet-dependent density of trap states. These results imply that controlling crystal grain and facet orientation will enable a systematic optimization of polycrystalline and single-crystal devices for photovoltaic and lighting applications.
UR - http://www.scopus.com/inward/record.url?scp=85017128412&partnerID=8YFLogxK
U2 - 10.1038/nenergy.2016.93
DO - 10.1038/nenergy.2016.93
M3 - Article
AN - SCOPUS:85017128412
SN - 2058-7546
VL - 1
JO - Nature energy
JF - Nature energy
IS - 8
M1 - 16093
ER -