Fig. 1.

Pyroelectricity of LN crystal bulk.a Schematic diagram of the pyroelectric working mechanism of the LN crystal wafer: the initial polarization state, the heated state, and the cooled state. Pyroelectric effects characterized using a heating element. b Photographs of the LN device with a piece of LN bulk wafer (2 cm × 2 cm). c A heating element used for the pyroelectric effect characterization. d Photographs of the heating element working with a DC power supply. e Pyroelectric current of the LN bulk under different temperatures. f Pyroelectric current of LN wafer with different change ranges and ramping rates of temperatures