Secondments at the Ecole Polytechnique Fédérale De Lausanne (EPFL)
Rashmi Runjhun, NaMeS PhD student, participated in the secondments at the Laboratory Of Photonics and Interfaces. She provided her research work in the distinguished lab of Prof. Michael Graetzel at EPFL Switzerland. Rashmi continued her research work on perovskite solar cells. She fabricated the solar cell devices following the procedures and techniques learnt during her last visit. The methods she used for the fabrication included chemical etching, spin coating, spray pyrolysis and vacuum evaporation. The aim of her project was to use ZnO quantum dots as the electron-transporting layer into the lead based planar perovskite solar cells structure. Rashmi prepared solutions of these quantum dots and deposited a thin film by spin coating. After optimizing the solution concentration, deposition parameters and annealing temperature of ZnO quantum dots, she was able to successfully fabricate high performance solar cells. She also incorporated two additional layers in order to further boost the efficiency of the devices. These layers improved the interface between the ZnO and perovskite layer which improved the device performance significantly. Rashmi Runjhun also collaborated in another project where was determined the structure of layered hybrid perovskites for a mixed-spacer model by nuclear magnetic resonance (NMR) crystallography. Using this structure it has been able to fabricate perovskite solar cells with higher power conversion efficiencies and better operational stability.
6 Jan, 2020.-31 Aug., 2020
Ecole Polytechnique Fédérale De Lausanne (EPFL), Switzerland