Growing up amidst the climate crisis inspired Nikhila Balasubramaniam to pursue a career aiding the green energy transition. Her interest in researching novel materials and technologies to advance clean energy motivated her to pursue a degree in Materials Science & Engineering, which led to her work on the degradation of perovskite solar cells (PSCs) as part of the Martin Research Group in EMSE.

Perovskite solar cells are a breakthrough technology for next-generation solar because of their champion efficiencies and solution-processability. Within a decade, 2012 to 2022, PSCs have progressed from 9.1% to 26% efficiency. Their solution-processability will make them easy and cheap to manufacture compared to the industry-standard polycrystalline silicon solar cells, without the materials availability challenges Si faces to reach TW(s) production. However, the widespread implementation of PSCs has been limited by stability and degradation issues with exposure to moisture and heat.

As a Spring 2023 SCSAM fellow, Nikhila has been using the ToF-SIMS to study how degradation occurs in PSCs and how small-molecule modifiers can be used to improve both the performance and lifetime of perovskite-based solar cells. Nikhila is using the ToF-SIMS to probe interlayer diffusion of elements that occurs during PSC degradation, and whether the application of small organofunctional silane modifiers can prevent that diffusion from occurring. ToF-SIMS allows Nikhila to determine the chemical profile of a film stack across its layers, and compare the functional, degraded and modified solar cells to each other. She can also correlate the chemical profile of the film stack to the film morphology and its subsequent stability.

The ToF-SIMS analyses completed during her SCSAM fellowship is a crucial part of Nikhila’s research project that she is doing with her mentor, Dr. Ina Martin. Nikhila has previously used the XPS in SCSAM, but this fellowship has allowed for in-depth experience with the ToF-SIMS. Nikhila would like to thank SCSAM Senior Research Engineer, Dr. John Kim, for diligently training her on operating the ToF-SIMS and helping her with data analysis. Dr. Kim said "it's been great seeing Nikhila persevere through grasping the ToF-SIMS depth profile technique and establishing the right parameters for her sample analysis. Nikhila is a quick and meticulous learner". Nikhila is “really thankful to the SCSAM fellowship for the introduction to ToF-SIMS” and “hopes to learn more spectroscopy” as she continues in her clean energy research career.