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  - 
TY  - JOUR
A1  - Braunger, Steffen
A1  - Mundt, Laura E.
A1  - Wolff, Christian Michael
A1  - Mews, Mathias
A1  - Rehermann, Carolin
A1  - Jost, Marko
A1  - Tejada, Alvaro
A1  - Eisenhauer, David
A1  - Becker, Christiane
A1  - Andres Guerra, Jorge
A1  - Unger, Eva
A1  - Korte, Lars
A1  - Neher, Dieter
A1  - Schubert, Martin C.
A1  - Rech, Bernd
A1  - Albrecht, Steve
T1  - Cs(x)FA(1-x)Pb(l(1-y)Br(y))(3) Perovskite Compositions
BT  - the Appearance of Wrinkled Morphology and its Impact on Solar Cell Performance
JF  - The journal of physical chemistry : C, Nanomaterials and interfaces
N2  - We report on the formation of wrinkle-patterned surface morphologies in cesium formamidinium-based Cs(x)FA(1-y)Pb(I1-yBry)(3) perovskite compositions with x = 0-0.3 and y = 0-0.3 under various spin-coating conditions. By varying the Cs and Br contents, the perovskite precursor solution concentration and the spin-coating procedure, the occurrence and characteristics of the wrinkle-shaped morphology can be tailored systematically. Cs(0.17)FA(0.83)Pb(I0.83Br0.17)(3) perovskite layers were analyzed regarding their surface roughness, microscopic structure, local and overall composition, and optoelectronic properties. Application of these films in p-i-n perovskite solar cells (PSCs) with indium-doped tin oxide/NiOx/perovskite/C-60/bathocuproine/Cu architecture resulted in up to 15.3 and 17.0% power conversion efficiency for the flat and wrinkled morphology, respectively. Interestingly, we find slightly red-shifted photoluminescence (PL) peaks for wrinkled areas and we are able to directly correlate surface topography with PL peak mapping. This is attributed to differences in the local grain size, whereas there is no indication for compositional demixing in the films. We show that the perovskite composition, crystallization kinetics, and layer thickness strongly influence the formation of wrinkles which is proposed to be related to the release of compressive strain during perovskite crystallization. Our work helps us to better understand film formation and to further improve the efficiency of PSCs with widely used mixed-perovskite compositions.
Y1  - 2018
U6  - https://doi.org/10.1021/acs.jpcc.8b06459
SN  - 1932-7447
SN  - 1932-7455
VL  - 122
IS  - 30
SP  - 17123
EP  - 17135
PB  - American Chemical Society
CY  - Washington
ER  -