Laser Processing in the Manufacture of Dye‐Sensitized and Perovskite Solar Cell Technologies

Abstract

Dye‐sensitized and perovskite solar cells have seen tremendous efforts in their development in recent years. Amongst these developments are the design and implementation of fabrication techniques that can guarantee high performance as well as scalability over large areas. Laser processing has become a versatile and important tool in many industries and has also been applied successfully to both types of solar cell technologies, culminating in the demonstration of dye solar devices where all temperature treatments have been replaced with laser techniques, and of high‐performance solid‐state perovskite modules. Herein, we introduce concepts and review the available literature, pertaining to the effective utilization of laser beams for the development of both dye‐sensitized and perovskite photovoltaic technologies.

Laser-Patterning Engineering for Perovskite Solar Modules With 95% Aperture Ratio

“…[21][22][23][24][25] The fabrication of perovskite modules needs additional materials and engineering efforts with respect to the small area cells, in particular, the laser patterning required to properly interconnect adjacent cells. [23,26] The structure of a typical monolithically connected n-i-p perovskite solar module is shown in Fig. 1 out comprises of the transparent substrate, the ETM, the perovskite absorber, the HTM and finally the back contact (usually gold).…”

“…The application of a ultra-short pulse laser permits the ablation of materials maintaining a very low heat diffusion through the target, since the time needed for the heat transfer from energized electrons to the lattice ions is in the order of nanoseconds [51] and an adequate picoseconds laser pulse power can evaporate irradiated material before heat transfer takes place. [26,51,52] Using a lens with a focal length of 150 mm, a beam waist w0 = 15 μm, and tuning the raster scanning speed, the raster scanning lines distance (RSD), and the laser fluence, we realized different TLM measurements to find the optimized process as shown in Fig. 2.…”

Research Update: Large-area deposition, coating, printing, and processing techniques for the upscaling of perovskite solar cell technology

“…The ability to precisely change the pattern (either for performance or aesthetical evaluation) is not only very useful for prototyping and development but also for manufacturing. The prime post-patterning process for perovskite solar cells is represented by laser processing as detailed in the review by Mincuzzi et al 11 A perovskite solar cell is composed of several layers with a thickness of a few hundred nanometers. Laser processing aims to pattern each layer avoiding damage to the underlying layers or TCO substrate.…”

“…51 Patterning and shaping by means of lasers brings many advantages such as a very high precision, resolution, processing speed, automation, high selectivity, and low cost. 11 Laser patterning is able to reduce the dead areas in perovskite based modules, minimizing such areas used for contacts. 53 Patterning can be performed in three sequential steps (P1-P2-P3) used to create the necessary spacing/isolation for the electrodes of adjacent sub cells (P1-P3) and to isolate clean the contact areas (P3).…”

“…This is why high resolution patterning, with techniques such as raster laser systems, is implemented to maintain efficiencies over aperture areas. 11 Apart from vacuum processing [12][13][14] which plays an important role for deposition of the two electrodes, and can also be employed for depositing the transport and perovskite layers, a characteristic feature of perovskite solar cell technology is that of determining the two dimensional shape or patterns of one or more of its constituent layers over large substrate areas by utilizing, together with laser processing, methods adopted from both printing and coating industry. The quality and uniformity achieved for the layers, with typical thicknesses between 100 nm and 300 nm, is critical for the scale up process of this technology.…”