title: Evaluation of a Silicon90Sr Betavoltaic Power Source.
abstract: Betavoltaic energy converters (i.e., β-batteries) are attractive power sources because of their potential for high energy densities (>200 MWh/kg) and long duration continuous discharge (>1 year). However, conversion efficiencies have been historically low (<3%). High efficiency devices can be achieved by matching β-radiation transport length scales with the device physics length scales. In this work, the efficiency of c-Si devices using high-energy (>1 MeV) electrons emitted from90Sr as a power source is investigated. We propose a design for a >10% efficient betavoltaic device, which generates 1 W of power. A Varian Clinac iX is used to simulate the high-energy electrons emitted from90Sr, and a high efficiency c-Si photovoltaic cell is used as the converter. The measured conversion efficiency is 16%. This relatively high value is attributed to proper length scale matching and the generation of secondary electrons in c-Si by the primary β-particles.
authors.affiliation: G. W. W. School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia, 30332, USA.
authors.forename: Jefferson
authors.initials: J
authors.lastname: Dixon
authors.affiliation: G. W. W. School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia, 30332, USA.
authors.forename: Aravindh
authors.initials: A
authors.lastname: Rajan
authors.affiliation: G. W. W. School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia, 30332, USA.
authors.forename: Steven
authors.initials: S
authors.lastname: Bohlemann
authors.affiliation: Department of Mechanical Engineering, Stanford University, California 94305, USA.
authors.forename: Dusan
authors.initials: D
authors.lastname: Coso
authors.affiliation: School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
authors.forename: Ajay D
authors.initials: AD
authors.lastname: Upadhyaya
authors.affiliation: School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
authors.forename: Ajeet
authors.initials: A
authors.lastname: Rohatgi
authors.affiliation: Department of Physics, Stanford University, California 94305, USA.
authors.forename: Steven
authors.initials: S
authors.lastname: Chu
authors.affiliation: Department of Mechanical Engineering, Stanford University, California 94305, USA.
authors.forename: Arun
authors.initials: A
authors.lastname: Majumdar
authors.affiliation: G. W. W. School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia, 30332, USA.
authors.forename: Shannon
authors.initials: S
authors.lastname: Yee