Design And Preparation Of Beta Radioluminescent Nuclear Batteries And Effect Of Temperature On Its Performances

The microbattery technology is one of the core technologies for the future development of Micro Electro-Mechanical Systems(MEMS). However, the existing microbattery technology can't meet the power requirements of long service time, without refueling and stable performance of MEMS for space application. A new type of beta radioluminescent nuclear battery with indirect-conversion of “nuclear energy – light energy – electric energy” was researched in this thesis, which can satisfy the demands of MEMS for space application. This thesis focuses on structure design, parameter optimization, sample preparation of the beta radioluminescent nuclear battery and the effect of ambient temperature on its performance.1) A beta radioluminescent nuclear battery based on a sandwich-structure 147Pm/Zn S:Cu /photovoltaic module was designed theoretically. MCNP software, Kubelka-Munk theory, detailed balance limit of efficiency and Shockley equation were used to analyze and calculate. The research results reveal that the thickness of isotope source, thickness of phosphor layer and bandgap of semiconductor exercise an influence on the output performance of the nuclear battery. And, the optimum parameter and corresponding output performance of the nuclear battery were obtained. Under the radiation of the 147 Pm source with a mass thickness of 5.92 mg/cm2, the optimal thickness of Zn S:Cu phosphor layer and the best bandgap of the semiconductor are 12.8 mg/cm2 and 2.075 e V, respectively. At the same time, 45.1 ?W/cm2 of maximum output power density Pmax, 15.36 ?A/cm2 of short-circuit current density Jsc, 3.2 V of open-circuit voltage Voc and 2.6% of energy conversion efficiency ?T were obtained for the nuclear battery.2) Beta radioluminescent nuclear batteries based on 147 Pm source, six types of phosphor layers and Ga As photovoltaic module were manufactured. Different thicknesses of phosphor layers were prepared using physical method. The optical performance of these phosphor layers and the output performance of the batteries loaded by these phosphor layers were measured, respectively. The study indicates that the spectrum of Zn S:Cu phosphor layer is the best match with Ga As photovoltaic cell. The radioluminescent intensity of Zn S:Cu phosphor layer with a mass thickness of about 11 mg/cm2 is greatest under the radiation of the 147 Pm source with a density of activity of 2.9 m Ci/cm2, which makes the battery with a higher energy conversion efficiency.3) The effect of ambient temperature on 147Pm/Zn S:Cu/Ga As beta radioluminescent nuclear battery was studied in the thesis. The experimental results show that Jsc decreases slightly, but Voc and Pmax rapidly reduce with the increase of temperature. As the same time, the thesis calculated theoretically the effect of temperature on the nuclear battery according to Shockley equation. The results of theoretical calculation similar to experimental values were obtained.The research work of this thesis provides an importance basis for optimization design, manufacture of the new type of radioluminescent nuclear battery, and will vigorously promote the application of nuclear batteries as the micro power source of MEMS devices. Meanwhile, the research work established the technical basis for further research of the nuclear microbattery for space application.