%AHeuser, T.%AHeuser, T. [Department of Materials Science and Engineering, Stanford University, 450 Serra Mall, Stanford, California 94305, USA]%ABraun, M. [Department of Materials Science and Engineering, Stanford University, 450 Serra Mall, Stanford, California 94305, USA]%ABraun, M.%AMcIntyre, P.%AMcIntyre, P. [Department of Materials Science and Engineering, Stanford University, 450 Serra Mall, Stanford, California 94305, USA]%ASenesky, D.%ASenesky, D. [Department of Aeronautics and Astronautics, Stanford University, 450 Serra Mall, Stanford, California 94305, USA, Department of Electrical Engineering, Stanford University, 450 Serra Mall, Stanford, California 94305, USA]%BJournal Name: Journal of Applied Physics; Journal Volume: 130; Journal Issue: 17; Related Information: CHORUS Timestamp: 2023-08-08 02:14:09 %D2021%IAmerican Institute of Physics %JJournal Name: Journal of Applied Physics; Journal Volume: 130; Journal Issue: 17; Related Information: CHORUS Timestamp: 2023-08-08 02:14:09 %K %MOSTI ID: 10306535 %PMedium: X %TElectron beam irradiation of gallium nitride-on-silicon betavoltaics fabricated with a triple mesa etch %X

A process for growing gallium nitride (GaN) vertical p–i–n homojunctions on (111) silicon substrates using metalorganic chemical vapor deposition was developed, and a triple mesa etch technique was used to fabricate efficient betavoltaic energy converters. Monte Carlo simulation platform CASINO was used to model beta radiation penetration into GaN to aid device design. The resulting devices were tested under irradiation from a scanning electron microscope electron beam (e-beam) tuned to imitate the energies of the 63Ni beta emission spectrum. Based on current–voltage measurements taken under e-beam illumination, a maximum open-circuit voltage of ∼412 mV and a maximum short-circuit current density of ∼407 nA/cm2 were measured. A high fill factor of ∼0.77 and power conversion efficiency of ∼6.6% were obtained. Additionally, the proposed triple mesa etch technique used to create these betavoltaics has the potential for further use in fabricating many types of electronic devices using a wide variety of material platforms.

%0Journal Article