Laser direct writing based flexible solar energy harvester

With the rapid advancement of flexible electronics, conventional rigid batteries, which serve as energy devices for flexible electronics, are no longer capable of meeting developmental requirements. In this context, solar cells, as an eco-friendly, low-carbon, and sustainable energy technology, have gained significant recognition. This paper aims to design a flexible solar energy harvester (FSEH) based on laser direct writing. The FSEH is comprised of commercial PET/PI films, flexible Cu circuits, and amorphous silicon solar cells which provide excellent flexibility and sustainability. The FSEH was formed by soldering the solar collection array to the laser direct-written flexible Cu circuit by using solder paste. The solar energy harvesting array consists of six sets of series-connected amorphous silicon solar cell arrays, with each set comprised of six amorphous silicon solar cells connected in parallel. It has a maximum light collection area of about 2772 mm2. The designed FSEH could generate energy by harvesting light energy from lights or solar radiation. The FSEH outputs 0.437 mW at the light intensity of 3000 Lux and 1.813 mW at the light intensity of 10,000 Lux. The FSEH maintains an output efficiency of over 92% with a bending angle of less than 45 degrees. Based on laser direct writing technology which enables efficient, convenient, and large-scale production of FSEH, the FSEH is expected to form a flexible selfpowered system with flexible supercapacitors and wearable electronics, and FSEH offers great advantages for the sustainable development of wearable electronics and flexible sensors.