Session: MNS-01 MEMS/NEMS Power Sources, Sensors and Actuators, and Computing

Paper Number: 74867

Start Time: August 17, 11:10 AM

74867 - Ingap Based Hybrid Pv-Bv Device Characterization 

Chemical cells discharge in a relatively short time, limiting their applications in autonomous devices.  WBG semiconductors are found to be useful in direct conversion of beta kinetic energy into electric current for low-power radioisotope sources enabling persistent communications and sensing.  Semiconductors with wider band gaps than silicon (1.1 eV), have been found to be more radiation tolerant. Electron beam induced currents (EBIC) stimulated the semiconductor.  The EBIC system utilizing 3-16 kV electron beam and 1.2 nA simulated 200mCi tritium radioisotope activity levels.  The betavoltaic (BV) response from InGaP (1.86 eV) was measured showing energy conversion efficiency of 9%.  The measured results compare well to Monte-Carlo models of energy deposition from nuclear scattering in these materials.  Tritium loaded nitroxide-gel has been deposited on InGaP creating a novel hybrid PV-BV energy generator. 

The betavoltaic process is similar to photovoltaic energy conversion, but in place of converting photon (sun) to electrical power, it uses beta-emitting isotopes to convert nuclear power to electrical power in a semi-conductor. The beta particles emitted by the isotopes have very high energy (1-100 keV) compared to optical photons (<6 eV) in order to create electron-hole pairs in semi-conductors. A betavoltaic device is made of a layer of beta-emitting isotope placed adjacent to asemiconductor p-n junction generally. Betavoltaic power sources have high energy density, long life span, feature durability in extreme environments such as space applications, under water, battle fields where the need to change batteries is inconvenient and where the use of chemical batteries is limited. 

Presenting Author: Mohamed Doumbia ARL

Authors:

Mohamed Doumbia ARL