Strong pyroelectric response in semiconducting Y-Ba-Cu-O and its application to uncooled infrared detection

A pyroelectric infrared detector operating at room temperature and based on semiconducting Y-Ba-Cu-O was fabricated. The capacitor structure consisting of semiconducting Y-Ba-Cu-O layer sandwiched between two Nb electrodes was fabricated on top of a thermally isolated SiO2 bridge. The polycrystalline Y-Ba-Cu-O layer was deposited by ambient-temperature sputtering while standard Si micromachining techniques were used to etch the silicon under the oxide bridge. The pyroelectric response of the material is characterized by the temperature coefficient of polarization (p=dP/dT) which was measured to be as high as 65 nC/K cm(2) without an externally applied electric field. The pyroelectric figure of merit F-d for the material was estimated to be 0.032 (cm(3)/J)(1/2). Employing a radiometric infrared source, the room-temperature voltage responsivity R-V and specific detectivity D* of the unbiased detector were measured to be over 10(3) V/W and 10(8) cm Hz(1/2)/W, respectively. This letter discusses the characteristics of this complementary metal-oxide semiconductor-compatible pyroelectric detector and suggests methods for the improvement for its figures of performance. (C) 1997 American Institute of Physics.