Cmos-Mems SC0.12AL0.88N-Based Pyroelectric Infared Detector with CO2 Gas Sensing

Pyroelectric IR detector is fabricated using ScAlN with 12% doped Sc as the pyroelectric sensing material. Dielectric layers that act as absorber are added on top of the ScAlN to help in IR absorption. This ScAlN-based pyroelectric detector is characterized by illumination from a MEMS thermal emitter with a sinusoidal input waveform. D* is measured to be as high as 1.87 x 10
⁷
(cm√Hz)/W at a frequency of 13 Hz. The optical absorptance of this device at 4.26 μm CO
₂
gas absorption wavelength is around 0.75, measured using FTIR. CO
₂
gas sensing measurement detects electrical signal changes of ~50-100 μV.