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SUMMARY:Towards High Performance Perovskite-Based Tandem PV - 2D/3D Perovs
 kite Heterostructures Enable High Open Circuit Voltage Wide-Bandgap Perovs
 kite Solar Cells
DTSTART:20190517T140000
DTEND:20190517T150000
DTSTAMP:20260408T055947Z
UID:ffc403cef427834253d2529512debf7bd02aacebaf49f21e5d3a97b9
CATEGORIES:Conferences - Seminars
DESCRIPTION:Par Dr. Ulrich W. Paetzold\nInstitute of Microstructure Techno
 logy (IMT)\, Hermann-von-Helmholtz-Platz 1\, 76344 Eggenstein-Leopoldshaf
 en\, Germany. Light Technology Institute (LTI)\, Engesserstrasse 13\, Bu
 ilding 30.34\, 76131 Karlsruhe\, Germany\n\nAbstract: The material class 
 of mixed-halide organic-inorganic hybrid perovskites exhibits a tunable ba
 ndgap from 1.2 - 3.1 eV\, simply by adjusting the ratio of the halide prec
 ursors. This property makes these materials excellent candidates for low-c
 ost multi-junction photovoltaics (PV). In particular\, wide-bandgap perovs
 kites (WBP) with a bandgap ranging between EG ~ 1.7 - 1.8 eV are attracti
 ve top-cell materials to improve the power conversion efficiency (PCE) of 
 single-junction crystalline silicon or thin-film CIGS solar cells in multi
 -junction PV. However\, obtaining high open-circuit voltage (VOC)\, which 
 is a mandatory requirement to achieve sufficient PCE\, is still a key chal
 lenge for WBP solar cells. In this contribution\, we report on wide-bandg
 ap perovskite solar cells with a stable power output efficiency of up to 1
 9.4% and a remarkable VOC of up to 1.31 V. The WBP solar cells in focus
  of this study employ a double-cation perovskite absorber layer based on F
 A and Cs in the composition FA0.83Cs0.17Pb(I0.6Br0.4)3 with a bandgap of 
 1.72 eV. By solution processing ammonium derivatives on top of the perovsk
 ite absorber layer\, an interlayer is introduced between the bulk 3D perov
 skite absorber layer and the hole transport layer. As we will show by mean
 s of XRD studies\, this interlayer is composed of 2D Ruddlesden-Popper per
 ovskites in intermediate phases ofn = 2\, resulting in a thin 2D/3D perov
 skite heterostructure at the hole extracting side of the solar cell. The d
 evices with 2D/3D heterostructure achieve an enhancement in VOC of up to
  80 mV\, leading to a stable record VOC for WBPs (EG ~ 1.72 eV) of up t
 o 1.31 eV. This very remarkable VOC reaches > 90% of the Shockley Queiss
 er (SQ) limit and corresponds to one of the highest ratios of VOC-to-EG 
 (0.76) reported for any perovskite solar cell with decent PCE. The device
 s with 2D/3D perovskite heterostructure show negligible hysteresis and dem
 onstrate very high PCE of 19.8% with corresponding stable power output e
 fficiency of 19.4% under continuous illumination of one sun irradiation in
 tensity and maximum power point tracking. The stable performance and high 
 reproducibility of the perovskite solar cells employing the 2D/3D perovski
 te heterostructure was proven further by providing data on the statistics 
 of > 50 devices.\n\n[1] S. Gharibzadeh\, B. Abdollahi Nejand\, M. Jakob
 y\, T. Abzieher\, D. Hauschild\, S. Moghadamzadeh\, J. A. Schwenzer\,
  P. Brenner\, R. Schmager\, A. Haghighirad\, L. Weinhardt\, U. Lemmer
 \, B. S. Richards\, I. A. Howard\, and U.W. Paetzold\, Adv. Energy Ma
 ter. 1803699 (2019) [DOI: 10.1002/aenm.201803699].\n\nDr. Ulrich W. Paet
 zold leads the research group Advanced Optics and Materials for Next Gener
 ation Photovoltaics at Karlsruhe Institute of Technology. He was a doctor
 al student at Forschungszentrum Jülich and received his PhD in physics f
 rom RWTH Aachen University\, then continued as a postdoc at imec in Leuve
 n. In 2016\, he was awarded an independent research group at Karlsruhe Ins
 titute of Technology. His research focusses on the interaction between li
 ght and structured matter for the purpose of engineering novel optical co
 ncepts and nanophotonic materials for solar energy harvesting. He is part
 icularly interested in perovskite thin-film and perovskite-based multijunc
 tion PV.
LOCATION:Seminar room CH G1 495 https://plan.epfl.ch/?room==CH%20G1%20495
STATUS:CONFIRMED
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