Research and preparation of two-dimensional plane arrays thermal imaging sensor

Abstract

Infrared imaging systems have been applied widely, and developed step by step with improved performance of infrared image devices. Although a thermocouple prepared by high quality thermoelectric materials has already been used as thermoelectric detectors, it is of new exploration when used as units of two-dimensional plane array thermal imaging sensors. In this paper, the working principle, device design, manufacturing process, device performance and measurement of two-dimensional plane array sensors are introduced and given in detail. The prepared thermal imaging sensors with 10 /spl times/ 10 pixels in 20 /spl times/ 20 mm/sup 2/ are made up of thermocouples with a single pixel of dimension of 0.4 /spl times/ 0.4 /spl times/ 0.15 mm/sup 3/ and prepared by pseudo-ternary BiTe thermoelectric materials with figure of merits Z=3.09 /spl times/ 10/sup -3/ K. The unit area for accepting thermal radiation is 1.9 /spl times/ 1.9 mm/sup 2/. The performance of the pixels and their uniformity in the arrays is measured respectively. From measurements, the maximum responsivity 0.12 V/W, detectability D* 1.17 /spl times/ 10 Hz/sup 1/2//W and responsive-time 24 ms of the thermal image arrays are obtained. The experimental results and theoretical analyses were compared, based on which, new ways for improving two-dimensional plane arrays thermal imaging sensors are proposed in this paper.