Kirthi Tennakone is a Sri Lankan scientist with an assortment of research interests in theoretical and experimental physics, chemistry and biological systems. He has authored over 350 publications covering a diverse variety of disciplines. He is the former Director of Institute of Fundamental Studies, Sri Lanka (now named as National Institute of Fundamental Studies) and the first Professor of Physics at the University of Ruhuna, Sri Lanka. He pursued studies leading to a doctoral degree in Theoretical Physics at the University of Hawaii under supervision of Sandip Pakvasa. Pakvasa and Tennakone were the first to suggest that neutrinos may be massive and to consider the astrophysical implications. In condensed matter physics, Tennakone pioneered the studies on semiconducting properties copper(I) thiocyanate, a rare example of a transparent p-type semiconductor, currently adopted in many devices and developed techniques of its deposition as thin films. He was the first to introduce the concept of the dye-sensitized solid state solar cell and demonstrate a working prototype of the same. Sri Lanka Government recognized his contribution to research and education and awarded National Honors on two occasions. He was one of the Union of Concerned Scientists who signed to the document presented to world leaders in 1992 about environmental degradation that threatens global life support systems on this planet. Early life Born 1940 in a Village in Sri Lanka near the town of Veyangoda, he was exposed rural environment in early childhood. He is a son of the poet and writer Piyathilaka Tennakone of Metitotumulla, Sri Lanka who inspired him to science and mathematics at an early stage. Kirthi Tennakone received primary education at the Central College, Veyangoda, Sri Lanka. Education He earned a B.S in physics and mathematics from the University of Ceylon 1964. After serving as a teacher in the Department of Education for period of four years, he received an East-West Center Fellowship to pursue studies at the University of Hawaii and obtained a PhD degree in theoretical physics in 1972. He returned to Sri Lanka accepting an academic position at the University of Jayewardenepura and later appointed to the Chair of Physics at the University of Ruhuna. When the first endowed Chair in Sri Lanka (Sumanasekara Chair in Natural Science) was commissioned at the Institute of Fundamental Studies, he was appointed to this position by the President of Sri Lanka on basis of the recommendation of a high ranking search committee.