Organometallic halide perovskites: sharp optical absorption edge and its relation to photovoltaic performance

0432513 - FZÚ 2015 RIV US eng J - Článek v odborném periodiku
De Wolf, S. - Holovský, Jakub - Moon, S.J. - Löper, P. - Niesen, B. - Ledinský, Martin - Haug, F.J. - Yum, J. H. - Ballif, C.
Organometallic halide perovskites: sharp optical absorption edge and its relation to photovoltaic performance.
Journal of Physical Chemistry Letters. Roč. 5, č. 6 (2014), s. 1035-1039. ISSN 1948-7185
Institucionální podpora: RVO:68378271
Klíčová slova: energy conversion and storage * energy and charge transport * perovskite
Kód oboru RIV: BM - Fyzika pevných látek a magnetismus
Impakt faktor: 7.458, rok: 2014

Solar cells based on organometallic halide perovskite absorber layers are emerging as a high-performance photovoltaic technology. Using highly sensitive photothermal deflection and photocurrent spectroscopy, we measure the absorption spectrum of CH3NH3PbI3 perovskite thin films at room temperature. We find a high absorption coefficient with particularly sharp onset. Below the bandgap, the absorption is exponential over more than four decades with an Urbach energy as small as 15 meV, which suggests a well-ordered microstructure. No deep states are found down to the detection limit of 1cm−1. These results confirm the excellent electronic properties of perovskite thin films, enabling the very high open-circuit voltages reported for perovskite solar cells. Following intentional moisture ingress, we find that the absorption at photon energies below 2.4 eV is strongly reduced, pointing to a compositional change of the material.
Trvalý link: http://hdl.handle.net/11104/0236850