Organic photovoltaic have experienced unprecedented improvement due to the synthesis of novel high-performing materials. Over the last years, thousands of novel organic semiconductors have been screened to evaluate their potential in photovoltaics. One of the major bottlenecks in the material evaluation is, however, the large amount of resources, time and material required for the device optimization. The authors circumvent this bottleneck by shifting from fabrication-intense to measurement-intensive assessment methods, enabling rapid multi-parametric optimization of novel organic photovoltaic systems.
The developed platform combines the fabrication of samples with gradients in the parameters of interest and advanced electrical and optical co-local evaluation images. The gradient sample is manufactured by doctor blading varying the blade speed profile (thickness gradients) with multichannel dispenser (composition gradients) and position-temperature dependent hot plate (annealing gradients). Then photocurrent and Raman maps enable the correlation of device performance and the thickness, composition and annealing temperature. The main advantage of this high-throughput methodology is that it allows a reduction in the evaluation times up to two orders of magnitude, and, at the same time, it saves around 90% of material. To show the generality of this high-throughput approach, three different photovoltaic system were optimized, namely PCDTBT:PC70BM, PTB7‐Th:PC70BM and PffBT4T‐2OD:PC70BM, employing less than 10 mg of each material in the entire process, yielding efficiencies of 5 %, 8 %, and 9.5 %, respectively.
Antonio Sánchez‐Díaz,1 Xabier Rodríguez‐Martínez,1 Laura Córcoles‐Guija,1 Germán Mora‐Martín1 and Mariano Campoy‐Quiles1
High‐Throughput Multiparametric Screening of Solution Processed Bulk Heterojunction Solar Cells.
Advanced Electronic Materials, 4, 1700477 (2018)
Artist’s rendering of the high-throughput combinatorial methodology. From doctor-bladed devices with composition gradients to non-invasive Raman and photocurrent imaging to identify the values of thickness and composition that result in maximum performance. Artist: Gustavo Regalado