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 170-340K. Temperature dependences of the monolayer and interbedded ⁶³Ni-Si betavoltaics at 213.15-333.15K 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 V_oc and P_max 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 V_oc and P_max sensitivities of the lower betavoltaic with 4.90mCi/cm^{2 63}Ni, -2.230mV/K and -1.132%, respectively, were lower than those with 1.96mCi/cm^{2 63}Ni, -2.490mV/K and -1.348%, respectively. Compared with the calculated results, the prepared betavoltaics had lower V_oc sensitivity and higher P_max sensitivity. In addition, the measured V_oc 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 P_max sensitivity of the interbedded betavoltaic is equal to the average of those of the two monolayers.