@article{FenskeSchultzDagaretal., author = {Fenske, Markus and Schultz, Christof and Dagar, Janardan and Kosasih, Felix Utama and Zeiser, Andreas and Junghans, Cornelia and Bartelt, Andreas and Ducati, Caterina and Schlatmann, Rutger and Unger, Eva and Stegemann, Bert}, title = {Improved Electrical Performance of Perovskite Photovoltaic Mini-Modules through Controlled PbI2 Formation Using Nanosecond Laser Pulses for P3 Patterning}, series = {Energy Technology}, volume = {9}, journal = {Energy Technology}, number = {4}, doi = {10.1002/ente.202000969}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:523-15841}, pages = {1 -- 8}, abstract = {The upscaling of perovskite solar cells to modules requires the patterning of the layer stack in individual cells that are monolithically interconnected in series. This interconnection scheme is composed of three lines, P1-P3, which are scribed using a pulsed laser beam. The P3 scribe is intended to isolate the back contact layer of neighboring cells, but is often affected by undesired effects such as back contact delamination, flaking, and poor electrical isolation. Herein, the influence of the laser pulse duration on the electrical and compositional properties of P3 scribe lines is investigated. The results show that both nanosecond and picosecond laser pulses are suitable for P3 patterning, with the nanosecond pulses leading to a higher open circuit voltage, a higher fill factor, and a higher power conversion efficiency. It is found that the longer pulse duration resultes in a larger amount of PbI2 formed within the P3 line and a thin Br-rich interfacial layer which both effectively passivate defects at the scribe line edges and block charge carrier in its vicinity. Thus, nanosecond laser pulses are preferable for P3 patterning as they promote the formation of beneficial chemical phases, resulting in an improved photovoltaic performance.}, subject = {Laserablation}, language = {en} } @article{ErdilKhenkinRemecetal., author = {Erdil, Ulas and Khenkin, Mark and Remec, Marko and Emery, Quiterie and Sudhakar, Vediappan and Schlatmann, Rutger and Abate, Antonio and Katz, Eugene A. and Ulbrich, Carolin}, title = {Mimicking Outdoor Ion Migration in Perovskite Solar Cells: A Forward Bias, No-Light Accelerated Aging Approach}, series = {ACS Energy Letters}, volume = {10}, journal = {ACS Energy Letters}, number = {3}, publisher = {American Chemical Society}, issn = {2380-8195}, doi = {10.1021/acsenergylett.5c00376}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:523-20205}, pages = {1529 -- 1537}, abstract = {Perovskite solar cells (PSCs) are expected to transform the photovoltaic market; however, their unproven operational stability requires urgent attention, particularly accelerated aging tests. Currently, illumination is the primary stressor in such tests. In this work, we present an accelerated aging procedure consisting of prolonged forward biasing followed by a dark storage (postbias rest) phase, conducted entirely in the dark. During aging under forward bias, ion migration led to impeded charge transport, macroscopic defect growth, and an adverse response of the cells to short light soaking, all of which recovered in the postbias rest phase, yet resulted in increased recombination due to redistribution of ions. We found that outdoor operation of PSCs in Berlin, Germany, over a 20-month period exhibited similar dynamics, with periods of higher temperature and irradiance (spring-summer) aligning with the forward bias phase and cooler, dimmer periods (fall-winter) aligning with the postbias rest phase. This paves the way for accelerated aging tests that can mimic ion migration-induced degradation outdoors without requiring an illumination source.}, subject = {Perowskit}, language = {en} }