Temperature dependence of 63Ni-Si betavoltaic microbattery

This paper theoretically presented the temperature effects on the 63Ni-Si betavoltaic microbattery irradiated by a source with different thicknesses and activity densities at a temperature range 170-340 K. Temperature dependences of the monolayer and interbedded 63Ni-Si betavoltaics at 213.15-333.15 K were tested with respect to calculations. Results showed that the higher the thickness, activity density, and average energy of the source, the lower is the betavoltaic performance responds to temperature. With the increase in temperature, the Voc and Pmax of the upper, lower, and interbedded betavoltaics decreased linearly at low temperatures and decreased exponentially at high temperatures in the experiment. As predicted, the measured Voc and Pmax sensitivities of the lower betavoltaic with 4.90 mCi/cm2 63Ni, −2.230 mV/K and −1.132%, respectively, were lower than those with 1.96 mCi/cm2 63Ni, −2.490 mV/K and −1.348%, respectively. Compared with the calculated results, the prepared betavoltaics had lower Voc sensitivity and higher Pmax sensitivity. In addition, the measured Voc sensitivity of the interbedded betavoltaic in series is equal to the sum of those of the upper and lower ones as predicted. Moreover, the measured Pmax sensitivity of the interbedded betavoltaic is equal to the average of those of the two monolayers.