Thermal detectors of uncooled multi-element infrared imaging Arrays. II. New thermally uninsulated elements

Abstract

A new approach to constructing the thermal element of a multi-element array on the basis of thin pyroelectric films is developed: the element is neither thermally insulated from the substrate nor separated by a gap from the substrate surface; instead, it operates owing to accumulation of the charge generated by infrared radiation during the frame. A new principle of high-speed modulation of radiation is described. Experimental results for the behavior of the pyroelectric coefficient in barium–strontium niobate films (Ba_xSr_1−xNb₂O₆), whose values reach up to (1–2)·10⁻³ C/m², are presented. It is demonstrated that the specific detectivity of sensitive elements 12 × 12 μm in size in the charge accumulation mode is greater than 10⁹ cm · Hz^0.5 ·W⁻¹.