TY  - JOUR
A1  - Kegelmann, Lukas
A1  - Tockhorn, Philipp
A1  - Wolff, Christian Michael
A1  - Márquez, José A.
A1  - Caicedo Dávila, Sebastián
A1  - Korte, Lars
A1  - Unold, Thomas
A1  - Loevenich, Wilfried
A1  - Neher, Dieter
A1  - Rech, Bernd
A1  - Albrecht, Steve
T1  - Mixtures of Dopant-Free Spiro-OMeTAD and Water-Free PEDOT as a Passivating Hole Contact in Perovskite Solar Cells
JF  - ACS applied materials & interfaces
N2  - Doped spiro-OMeTAD at present is the most commonly used hole transport material (HTM) in n-i-p-type perovskite solar cells, enabling high efficiencies around 22%. However, the required dopants were shown to induce nonradiative recombination of charge carriers and foster degradation of the solar cell. Here, in a novel approach, highly conductive and inexpensive water-free poly(3,4-ethylenedioxythiophene) (PEDOT) is used to replace these dopants. The resulting spiro-OMeTAD/PEDOT (SpiDOT) mixed films achieve higher lateral conductivities than layers of doped spiro-OMeTAD. Furthermore, combined transient and steady-state photoluminescence studies reveal a passivating effect of PEDOT, suppressing nonradiative recombination losses at the perovskite/HTM interface. This enables excellent quasi-Fermi level splitting values of up to 1.24 eV in perovskite/SpiDOT layer stacks and high open-circuit voltages (V-OC) up to 1.19 V in complete solar cells. Increasing the amount of dopant-free spiro-OMeTAD in SpiDOT layers is shown to enhance hole extraction and thereby improves the fill factor in solar cells. As a consequence, stabilized efficiencies up to 18.7% are realized, exceeding cells with doped spiro-OMeTAD as a HTM in this study. Moreover, to the best of our knowledge, these results mark the lowest nonradiative recombination loss in the V-OC (140 mV with respect to the Shockley-Queisser limit) and highest efficiency reported so far for perovskite solar cells using PEDOT as a HTM.
KW  - perovskite solar cell
KW  - selective contact
KW  - spiro-OMeTAD
KW  - PEDOT
KW  - recombination
KW  - passivation
KW  - quasi-Fermi level splitting
Y1  - 2019
U6  - https://doi.org/10.1021/acsami.9b01332
SN  - 1944-8244
SN  - 1944-8252
VL  - 11
IS  - 9
SP  - 9172
EP  - 9181
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Tockhorn, Philipp
A1  - Sutter, Johannes
A1  - Cruz Bournazou, Alexandros
A1  - Wagner, Philipp
A1  - Jäger, Klaus
A1  - Yoo, Danbi
A1  - Lang, Felix
A1  - Grischek, Max
A1  - Li, Bor
A1  - Li, Jinzhao
A1  - Shargaieva, Oleksandra
A1  - Unger, Eva
A1  - Al-Ashouri, Amran
A1  - Köhnen, Eike
A1  - Stolterfoht, Martin
A1  - Neher, Dieter
A1  - Schlatmann, Rutger
A1  - Rech, Bernd
A1  - Stannowski, Bernd
A1  - Albrecht, Steve
A1  - Becker, Christiane
T1  - Nano-optical designs for high-efficiency monolithic perovskite-silicon tandem solar cells
JF  - Nature nanotechnology
N2  - Designing gentle sinusoidal nanotextures enables the realization of high-efficiency perovskite-silicon solar cells <br /> Perovskite-silicon tandem solar cells offer the possibility of overcoming the power conversion efficiency limit of conventional silicon solar cells. Various textured tandem devices have been presented aiming at improved optical performance, but optimizing film growth on surface-textured wafers remains challenging. Here we present perovskite-silicon tandem solar cells with periodic nanotextures that offer various advantages without compromising the material quality of solution-processed perovskite layers. We show a reduction in reflection losses in comparison to planar tandems, with the new devices being less sensitive to deviations from optimum layer thicknesses. The nanotextures also enable a greatly increased fabrication yield from 50% to 95%. Moreover, the open-circuit voltage is improved by 15 mV due to the enhanced optoelectronic properties of the perovskite top cell. Our optically advanced rear reflector with a dielectric buffer layer results in reduced parasitic absorption at near-infrared wavelengths. As a result, we demonstrate a certified power conversion efficiency of 29.80%.
Y1  - 2022
U6  - https://doi.org/10.1038/s41565-022-01228-8
SN  - 1748-3387
SN  - 1748-3395
VL  - 17
IS  - 11
SP  - 1214
EP  - 1221
PB  - Nature Publishing Group
CY  - London [u.a.]
ER  -