The project results were in line with the proposed objectives, milestones, and deliverables. The work performed within this project included (a) rational molecular design and synthesis of the bulk and surface passivation materials for the development of robust absorber; (b) molecular design and synthesis of dopant free HTMs; (c) Structural, morphological and optoelectronic characterization of the developed absorbers at different length scale (several µm to few nm); (d) Structural, optoelectronic and electrochemical characterization of HTMs; (e) Device fabrication with the developed absorbers and HTMs (f) rigorous stability evaluation under different condition (moisture, heat, electric field, etc..) of the fabricated devices. (g) establishing structure-property relationships. This project has led to several key results and findings, some of which have been published in top peer-reviewed journals, and several manuscripts are under preparation.
Our work titled: Our work titled: Nanoscale interfacial engineering enables highly stable and efficient perovskite photovoltaics (Energy Environ. Sci., 2021,14, 5552-5562, Impact factor = 38.5) has been a breakthrough study on molecular engineering of the interface in PSCs. In this study, we developed a facile molecular-level interface engineering strategy using a multifunctional ligand, which augments the stability of single-junction solar cells. The results of the work offer recommendations to expedite the design strategies of passivating ligands and are expected to stimulate further work on the fundamental understanding of interfacial ion diffusion mechanisms to facilitate stable and efficient PSCs. In this study's follow-up, we have designed a series of interface materials, leading to a high PCE of 24 % and excellent long-term stability. Using multiscale characterization and modeling techniques, we establish the correlation between the molecular design, interaction and the interface defects, and interfacial ion diffusion. So far, there is no clear understanding of interface ion diffusion; thus, this work is expected to improve its understanding. Currently, this manuscript is under preparation.
In another study, we develop a facile 2D/3D interface engineering strategy using supramolecular chemistry. This approach has led to PSCs with a PCE of > 24 % with excellent long-term operational stability. Further, we employ solid-state nuclear magnetic resonance (ss-NMR), photoluminescence, and scanning tunneling spectroscopy to unravel critical insights of the 2D/3D interface. Currently, this manuscript is under preparation.
We also have developed two new HTMs. The devices fabricated using these HTMs show better performance and stability than those fabricated from classical HTM (Spiro-OMeTAD). Currently, the manuscript is in preparation. Apart from journal publications, results and findings were presented in several top conferences and media outlets.
