Gwangju Institute of Science and Technology (GIST) has announced they have developed a new module architecture using ionic-conducting features of perovskites to create metal-filamentary nanoelectrodes in the series connection region.
Currently, the fabrication of large-area perovskite photovoltaic modules without efficiency losses has been considered as an important factor for the commercialisation of photovoltaics. Especially, the ratio between the photoactive area and total area, the so called geometrical fill factor, should be high for the efficient photovoltaic modules.
A research group led by Kwanghee Lee (Professor, School of Materials Science & Engineering & Heeger Center for Advanced Materials & Research Institute for Solar and Sustainable Energies, GIST) demonstrate an electrochemical patterning process improving a geometrical fill factor up to 94.1%. Thus, a high module efficiency of 14.0% was achieved in the planar type perovskite photovoltaic modules with the area of 9.06 cm2.
By applying an electric field to the series connection regions, the metal ion diffused to anode and recombined with electrons, thereby forming conductive metal-filamentary nanoelectrodes and then creating series interconnection between the adjacent subcells without laser scribing process. Direct evidence of the formation of metal-filamentary nanoelectrodes was provided by various analysis including scanning transmission electron microscopy (STEM), energy-dispersive spectroscopy (EDS), time-of-flight secondary ion mass spectroscopy (TOF-SIMS), x-ray photoelectron spectroscopy (XPS) and J-V measurements. From the analysis and the fabrication of photovoltaic modules, we conclude that metal-filamentary nanoelectrodes are clearly formed by electric fields in the series connection regions. Therefore, GIST is confident that the new patterning method accelerates the practical development of perovskite photovoltaic cells.
High-efficiency large-area perovskite photovoltaic modules achieved via electrochemically assembled metal-filamentary nanoelectrodes
Soonil Hong | Jinho Lee | Hongkyu Kang | Geunjin Kim | Seyoung Kee | Jong-Hoon Lee | Suhyun Jung | Byoungwook Park | Seok Kim | Hyungcheol Back | Kilho Yu | Kwanghee Lee1
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea.
- Heeger Center for Advanced Materials, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea.
- Department of Chemistry and Centre for Plastic Electronics, Imperial College London, London SW7 2AZ, UK.
- Research Institute for Solar and Sustainable Energies, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea.
Science Advances｜ DOI: 10.1126/sciadv.aat3604 ｜ Publication Date: August 17, 2018
Abstract
Realizing industrial-scale, large-area photovoltaic modules without any considerable performance losses compared with the performance of lab-scale, small-area perovskite solar cells (PSCs) has been a challenge for practical applications of PSCs. Highly sophisticated patterning processes for achieving series connections, typically fabricated using printing or laser-scribing techniques, cause unexpected efficiency drops and require complicated manufacturing processes. Here, we successfully fabricated high-efficiency, large-area PSC modules using a new electrochemical patterning process. The intrinsic ion-conducting features of perovskites enabled us to create metal-filamentary nanoelectrodes to facilitate the monolithic serial interconnections of PSC modules. By fabricating planar-type PSC modules through low-temperature annealing and all-solution processing, we demonstrated a notably high module efficiency of 14.0% for a total area of 9.06 cm2 with a high geometric fill factor of 94.1%.