Resonant and resistive dual-mode uncooled infrared detectors toward expanded dynamic range and high linearity

Abstract

This paper reports an uncooled infrared (IR) detector based on a micromachined piezoelectric resonator operating in resonant and resistive dual-modes. The two sensing modes achieved IR responsivities of 2.5 Hz/nW and 900 μdB/nW, respectively. Compared with the single mode operation, the dual-mode measurement improves the limit of detection by two orders of magnitude and meanwhile maintains high linearity and responsivity in a higher IR intensity range. A combination of the two sensing modes compensates for its own shortcomings and provides a much larger dynamic range, and thus, a wider application field of the proposed detector is realized.

Dual functionality metamaterial enables ultra-compact, highly sensitive uncooled infrared sensor

“…TCF is usually an intrinsic property of materials that is dependent on the growth conditions. The TCF of the proposed device is comparable with previously reported values [3,5,36]. Figure 2c also shows that the proposed sensor has a large linear dynamic range, which is beneficial for practical applications.…”

“…The responsivity can also be expressed as 110 Hz/nW over the sensing area of 15,000 μm 2 . This result indicates a much higher sensitivity than those of previous reports [3,5]. The results also exhibit good linearity and a large dynamic range.…”

“…FBARs, which feature a high temperature-sensitivity, must be seen here as an advantage since it can be applied to uncooled infrared sensors [3][4][5][6]. Indeed, upon infrared radiation, the temperature of the FBAR increases, while the resonance frequency decreases due to its negative temperature-frequency coefficient.…”

“…In this category of FBAR-based uncooled infrared detectors, Ang [4] developed an aluminum nitride (AlN) Lamb wave mode resonator and found that the sensing mechanism is based on both charge carrier generation and thermal effects. Xin [5] reported a resonant and resistive dual-mode resonator. Wang [6] used ZnO films and achieved a noise equivalent temperature difference (NETD) of 25 mK at 780 nm.…”

Polyimide-Based High-Performance Film Bulk Acoustic Resonator Humidity Sensor and Its Application in Real-Time Human Respiration Monitoring

“…As the humidity sensitive layer, PI enhanced the humidity sensitivity to +67.3 kHz/%RH (64 ppm/%) between 15%RH and 85%RH with a sufficient Q (>200), which is 39 times higher than the sample without PI film. Inspired by the improved sensor performance by two-parameter detection, such as resonant frequency and resistance [ 29 ], resonant frequency and reflection coefficient S 11 [ 30 ], we further investigated the reflection coefficient S 11 response of the PI-FBAR humidity sensor [ 25 ]. Results showed that an ultra-high average humidity sensitivity of 0.044 dB/%RH (2095 ppm/%RH) was achieved, and the sensitivity at 20% low relative humidity reached 0.075 dB/%RH (3571 ppm/%RH), which is more than two orders of magnitude higher than that of the resonant frequency response.…”