Timing A Pulsed Thin Film Pyroelectric Generator For Maximum Power Density

[摘要] Pyroelectric thermal-to-electric energy conversion is accomplished by a cyclic process of thermally-inducing polarization changes in the material under an applied electric field. The pyroelectric MEMS device investigated consisted of a thin film PZT capacitor with platinum bottom and iridium oxide top electrodes. Electric fields between 1-20 kV/cm with a 30% duty cycle and frequencies from 0.1 - 100 Hz were tested with a modulated continuous wave IR laser with a duty cycle of 20% creating temperature swings from 0.15 - 26 C on the pyroelectric receiver. The net output power of the device was highly sensitive to the phase delay between the laser power and the applied electric field. A thermal model was developed to predict and explain the power loss associated with finite charge and discharge times. Excellent agreement was achieved between the theoretical model and the experiment results for the measured power density versus phase delay. Limitations on the charging and discharging rates result in reduced power and lower efficiency due to a reduced net work per cycle.

[发布机构] U.S. Naval Academy, Annapolis; MD; 21402, United States^1;U.S. Army Research Laboratory, Adelphi; MD; 20783, United States^2

[效力级别] 能源学

[关键词] Charge and discharge;Continuous Wave;Cyclic process;Electric energy conversion;Iridium oxides;Power densities;Temperature swings;Theoretical modeling