@misc{PisoniStolterfohtLockingeretal.2019, author = {Pisoni, Stefano and Stolterfoht, Martin and Lockinger, Johannes and Moser, Thierry and Jiang, Yan and Caprioglio, Pietro and Neher, Dieter and Buecheler, Stephan and Tiwari, Ayodhya N.}, title = {On the origin of open-circuit voltage losses in flexible n-i-p perovskite solar cells}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1110}, issn = {1866-8372}, doi = {10.25932/publishup-45961}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-459617}, pages = {12}, year = {2019}, abstract = {The possibility to manufacture perovskite solar cells (PSCs) at low temperatures paves the way to flexible and lightweight photovoltaic (PV) devices manufactured via high-throughput roll-to-roll processes. In order to achieve higher power conversion efficiencies, it is necessary to approach the radiative limit via suppression of non-radiative recombination losses. Herein, we performed a systematic voltage loss analysis for a typical low-temperature processed, flexible PSC in n-i-p configuration using vacuum deposited C-60 as electron transport layer (ETL) and two-step hybrid vacuum-solution deposition for CH3NH3PbI3 perovskite absorber. We identified the ETL/absorber interface as a bottleneck in relation to non-radiative recombination losses, the quasi-Fermi level splitting (QFLS) decreases from similar to 1.23 eV for the bare absorber, just similar to 90 meV below the radiative limit, to similar to 1.10 eV when C-60 is used as ETL. To effectively mitigate these voltage losses, we investigated different interfacial modifications via vacuum deposited interlayers (BCP, B4PyMPM, 3TPYMB, and LiF). An improvement in QFLS of similar to 30-40 meV is observed after interlayer deposition and confirmed by comparable improvements in the open-circuit voltage after implementation of these interfacial modifications in flexible PSCs. Further investigations on absorber/hole transport layer (HTL) interface point out the detrimental role of dopants in Spiro-OMeTAD film (widely employed HTL in the community) as recombination centers upon oxidation and light exposure. [GRAPHICS] .}, language = {en} } @article{PisoniStolterfohtLockingeretal.2019, author = {Pisoni, Stefano and Stolterfoht, Martin and Lockinger, Johannes and Moser, Thierry and Jiang, Yan and Caprioglio, Pietro and Neher, Dieter and Buecheler, Stephan and Tiwari, Ayodhya N.}, title = {On the origin of open-circuit voltage losses in flexible n-i-p perovskite solar cells}, series = {Science and technology of advanced materials : STAM}, volume = {20}, journal = {Science and technology of advanced materials : STAM}, publisher = {Taylor \& Francis}, address = {Abingdon}, issn = {1468-6996}, doi = {10.1080/14686996.2019.1633952}, pages = {786 -- 795}, year = {2019}, abstract = {The possibility to manufacture perovskite solar cells (PSCs) at low temperatures paves the way to flexible and lightweight photovoltaic (PV) devices manufactured via high-throughput roll-to-roll processes. In order to achieve higher power conversion efficiencies, it is necessary to approach the radiative limit via suppression of non-radiative recombination losses. Herein, we performed a systematic voltage loss analysis for a typical low-temperature processed, flexible PSC in n-i-p configuration using vacuum deposited C-60 as electron transport layer (ETL) and two-step hybrid vacuum-solution deposition for CH3NH3PbI3 perovskite absorber. We identified the ETL/absorber interface as a bottleneck in relation to non-radiative recombination losses, the quasi-Fermi level splitting (QFLS) decreases from similar to 1.23 eV for the bare absorber, just similar to 90 meV below the radiative limit, to similar to 1.10 eV when C-60 is used as ETL. To effectively mitigate these voltage losses, we investigated different interfacial modifications via vacuum deposited interlayers (BCP, B4PyMPM, 3TPYMB, and LiF). An improvement in QFLS of similar to 30-40 meV is observed after interlayer deposition and confirmed by comparable improvements in the open-circuit voltage after implementation of these interfacial modifications in flexible PSCs. Further investigations on absorber/hole transport layer (HTL) interface point out the detrimental role of dopants in Spiro-OMeTAD film (widely employed HTL in the community) as recombination centers upon oxidation and light exposure. [GRAPHICS] .}, language = {en} } @article{LaiLuoZwirneretal.2022, author = {Lai, Huagui and Luo, Jincheng and Zwirner, Yannick and Olthof, Selina and Wieczorek, Alexander and Ye, Fangyuan and Jeangros, Quentin and Yin, Xinxing and Akhundova, Fatima and Ma, Tianshu and He, Rui and Kothandaraman, Radha K. and Chin, Xinyu and Gilshtein, Evgeniia and Muller, Andre and Wang, Changlei and Thiesbrummel, Jarla and Siol, Sebastian and Prieto, Jose Marquez and Unold, Thomas and Stolterfoht, Martin and Chen, Cong and Tiwari, Ayodhya N. and Zhao, Dewei and Fu, Fan}, title = {High-performance flexible all-Perovskite tandem solar cells with reduced V-OC-deficit in wide-bandgap subcell}, series = {Advanced energy materials}, volume = {12}, journal = {Advanced energy materials}, number = {45}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1614-6832}, doi = {10.1002/aenm.202202438}, pages = {12}, year = {2022}, abstract = {Among various types of perovskite-based tandem solar cells (TSCs), all-perovskite TSCs are of particular attractiveness for building- and vehicle-integrated photovoltaics, or space energy areas as they can be fabricated on flexible and lightweight substrates with a very high power-to-weight ratio. However, the efficiency of flexible all-perovskite tandems is lagging far behind their rigid counterparts primarily due to the challenges in developing efficient wide-bandgap (WBG) perovskite solar cells on the flexible substrates as well as their low open-circuit voltage (V-OC). Here, it is reported that the use of self-assembled monolayers as hole-selective contact effectively suppresses the interfacial recombination and allows the subsequent uniform growth of a 1.77 eV WBG perovskite with superior optoelectronic quality. In addition, a postdeposition treatment with 2-thiopheneethylammonium chloride is employed to further suppress the bulk and interfacial recombination, boosting the V-OC of the WBG top cell to 1.29 V. Based on this, the first proof-of-concept four-terminal all-perovskite flexible TSC with a power conversion efficiency of 22.6\% is presented. When integrating into two-terminal flexible tandems, 23.8\% flexible all-perovskite TSCs with a superior V-OC of 2.1 V is achieved, which is on par with the V-OC reported on the 28\% all-perovskite tandems grown on the rigid substrate.}, language = {en} }