Abstract: A world without energy is not a world indeed. Energy is required by every living daily life and its need is also increasing daily. Though we are still dependent on the sources like fossil fuels, natural gas, oils but these sources are limited, and also non-environment friendly, so renewable sources of energy came in light. Solar energy being one of the renewable sources has been one of the primary sources of energy and is highly abundant to capture and use. The solar cells or photovoltaic cells are the electrical device which can capture the solar energy which and convert the light to electrical energy which can be used for daily life. There are different solar based cells like the crystalline silicon based 1st generation solar cells; thin film based solar cells including the amorphous silicon based solar cells as well as the inorganic semiconductor based dye sensitizer solar cells and the very new perovskite cells are well known photovoltaic cells. Dye sensitized solar cells are flexible lightweight, low cost and highly efficient solar cells and are a prime research area. Recently, organic dye sensitized solar cells with a general structure of Donor-pi Spacer-Acceptor (D-π-A) have a very important area of research. A slight change in any part of the donor, spacer or the acceptor may lead to a change in the efficiency of the DSSCs.
Computational modelling has always been at par with the research on the DSSCs. Several studies on how the slight change in the parameters can have an effect on the efficiencies have been studied with Density Functional Theory calculations and the best one have been forwarded for the synthesis for experimental verification. I have been working on this field through in silico modelling in the last few years mainly contributing on both the metal organic and organic dye sensitized solar cells for n-type as well as p-type semiconductors. Here I would like to briefly talk about the effect on the DSSCs for the changes associated with the donors and the pi-spacers for both for n-type and p-type semiconductor based dyes. [1-5]

1. Dharmendra Biswal, Anjali Jha and Anik Sen*, J. Mol. Struct. 2021, 1228, 129776.
2. Anik Sen* and Axel Groβ, J. Phys. Chem. C 2020, 124, 8526-8540.
3. Anik Sen*, Stephan Kupfer, Stefanie Gräfe and Axel Groβ, 2020, J. Physics B: Atomic, Molecular and Optical Physics, 2020, 53, 234001.
4. Anik Sen* and Axel Groβ, ACS Applied Energy Materials, 2019, 2, 6341-6347
5. Anil Kumar Behera and Anik Sen*, J. Photochem. Photobiol. A, 2022, 433, 114146