The development of flexible perovskite solar modules requires reliable laser scribing processes to achieve monolithic interconnection and large-area integration. Among the key processing parameters, laser repetition rate plays an important role in determining the thermal interaction between consecutive laser pulses. At high repetition rates, the short intervals between pulses can limit heat dissipation, resulting in thermal accumulation around the scribing lines. This phenomenon can generate heat-affected zones (HAZ), potentially damaging adjacent functional layers and increasing inactive areas within the module. Therefore, controlling thermal accumulation during laser scribing is essential for minimizing HAZ and improving module fabrication quality. In this study, the effect of laser repetition rate on HAZ formation was investigated using flexible substrates, ITO-coated polyethylene naphthalate (ITO/PEN) and ITO-coated polyethylene terephthalate (ITO/PET). The objective was to understand the relationship between pulse intervals, heat diffusion, substrate-dependent thermal responses, and scribing quality. 

 The laser scribing characteristics were investigated under different repetition-rate conditions while considering pulse energy and pulse overlap to evaluate the influence of repetition rate on thermal accumulation. A lower repetition rate provides a longer time interval between consecutive pulses, allowing more heat to dissipate into the surrounding material before the next pulse arrives. Consequently, thermal accumulation can be suppressed, potentially reducing the width of the HAZ surrounding the scribing lines. In addition, ITO/PEN and ITO/PET substrates were compared to investigate how differences in substrate properties influence laser-induced thermal behavior. The resulting scribing profiles and HAZ dimensions were evaluated to identify the relationship between repetition rate and substrate-dependent laser interaction. These analyses provide insight into the optimization of laser processing conditions for flexible perovskite solar modules.

 This study proposes repetition-rate control as an effective strategy for minimizing HAZ during laser scribing of flexible perovskite solar modules. By increasing the heat diffusion time between consecutive pulses, lower repetition rates can potentially reduce thermal accumulation and preserve the surrounding functional regions. Furthermore, comparing ITO/PEN and ITO/PET substrates provides a basis for understanding substrate-dependent thermal responses and establishing optimized scribing conditions. Minimizing HAZ is expected to reduce inactive areas, increase the effective module area, and improve interconnection quality, ultimately contributing to enhanced device performance and scalable manufacturing of flexible perovskite solar modules.