CMOS compatible pyroelectric materials for infrared detectors

Abstract

The pyroelectric materials offer good performance at room temperature because of their high sensitivity and uniform spectral response in the wide infrared (IR) range. Out of various types of pyroelectric materials, CMOS (complementary metal-oxide-semiconductor) compatible materials are now in need because of the trend towards monolithic integration for the fabrication of a highly efficient miniaturized IR detector with low cost. Recent experimental results have led to significant advances in CMOS compatible pyroelectric materials, which indicate their potential applications in the development of IR detectors. This review summarises important CMOS compatible materials such as aluminium nitride (AlN), hafnium oxide (HfO2), zinc oxide (ZnO) and gallium nitride (GaN) along with their applications. The pyroelectric coefficient of CMOS compatible materials is found to be comparable with single-crystal pyroelectric materials including triglycine sulphate (TGS), lithium tantalate (LiTaO3), lithium niobate (LiNbO3) and different ceramic materials. The pyroelectric effect in materials is affected by various parameters namely growth technology, structures, dopant concentration, etc. The performance of pyroelectric materials for different applications is investigated by the figure of merits like voltage responsivity, current responsivity, detectivity and noise equivalent power.