Improved Electrical Performance of Perovskite Photovoltaic Mini‐Modules through Controlled PbI₂ Formation Using Nanosecond Laser Pulses for P3 Patterning

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.

Reducing Losses in Perovskite Large Area Solar Technology: Laser Design Optimization for Highly Efficient Modules and Minipanels

“…It has been demonstrated by Fenske et al. [ 14 ] that electrical performances of modules on the P3 process have been improved by using nanosecond pulses instead of picosecond ones. In this regards, using a 355 nm wavelength, in the UV region, allows having a wider working condition window, dealing with the removal of TCO (P1), Electron Transport Layer (ETL)/Perovskite/Hole Transport Layer (HTL) (P2), and metal (P3), with respect to the 532 nm (green region), or the 1064 nm (red region) wavelengths.…”

“…and metal foil, might need specific laser systems, giving priority to the lowest laser pulse system available (pico-to femtosecond) to reduce any damage causes to the substrate, with the counterpart of taking into account the exponential cost to obtain such systems. [13] It has been demonstrated by Fenske et al [14] that electrical performances of modules on the P3 process have been improved by using nanosecond pulses instead of picosecond ones. In this regards, using a 355 nm wavelength, in the UV region, allows having a wider working condition window, dealing with the removal of TCO (P1), Electron Transport Layer (ETL)/Perovskite/ Hole Transport Layer (HTL) (P2), and metal (P3), with respect to the 532 nm (green region), or the 1064 nm (red region) wavelengths.…”

Mechanochemistry Advances High‐Performance Perovskite Solar Cells

“…The performance drop of the samples with more PbI 2 could be attributed to the parasitic absorption losses and the large amount of nonradiative recombination sites derived from the redundant PbI 2 in perovskite films. [57,58] Also, the perovskite precursor with redundant PbI 2 inevitably suffers from process incompatibility and could produce byproducts that are harmful to the optoelectronic property of perovskites. These results indicate that the ball-milling process with excess FAI is critical to obtain stoichiometric-pure δ-FAPbI 3 , which is highly desirable to achieve high-performance PSCs.…”

Recent developments in perovskite-based precursor inks for scalable architectures of perovskite solar cell technology

“…162,173,201,204 This is understandable, since the post-processing methods such as selective laser scribing, followed by large-area coatings of active layers including the perovskite-based light absorbing layer by these schemes have been proposed to facilitate the production of established serially connected modules. [205][206][207] In contrast, other potential scalable methods such as dropon-demand inkjet printing 136,[208][209][210] have yet to be proven as a reliable process step for large perovskite layer deposition in order to overcome advanced key challenges related to creating exibility in pattern designs of any choice through high precision and resolution. 15,17,211 These challenges call for the development of room temperature-based chemically stable precursor inks that can pass through without clotting the micronozzles of the inkjet cartridges, in order to deliver precise microlitre-sized drop volumes over the desired surfaces.…”