Enhanced room-temperature terahertz detection and imaging derived from anti-reflection 2D perovskite layer on MAPbI3 single crystals

Terahertz (THz) detection technology is getting increasing attention from scientists and industries alike due to its superiority in imaging, communication, and defense. Unfortunately, the detection of THz electromagnetic waves under room temperature requires a complicated device architecture design or additional cryogenic cooling units, which increase the cost and complexity of devices, subsequently imposing an impediment in its universal application. In this work, THz detectors operated under room temperature are designed based on the thermoelectric effect with MAPbI(3) single crystals (SCs) as active layers. With solution-processed molecular growth engineering, the anti-reflection 2D perovskite layers were constructed on SCs' surfaces to suppress THz reflection loss. Simultaneously, by finely regulating the main carrier types and the direction of the applied bias across the inclined energy level, the thermoelectric effect is further promoted. As a result, THz-induced Delta T in MAPbI(3) SCs reaches 4.6 degrees C, while the enhancement in the bolometric and photothermoelectric effects reach similar to 4.8 times and similar to 16.9 times, respectively. Finally, the devices achieve responsivity of 88.8 mu A W-1 at 0.1 THz under 60 V cm(-1), noise equivalent power (NEP) less than 2.16 x 10(-9) W Hz(-1/2), and specific detectivity (D*) of 1.5 x 10(8) Jones, which even surpasses the performance of state-of-the-art graphene-based room-temperature THz thermoelectric devices. More importantly, proof-of-concept imaging gives direct evidence of perovskite-based THz sensing in practical applications.

Automated summary

This study presents a room temperature-operated terahertz (THz) detector based on MAPbI(3) single crystals with anti-reflection 2D perovskite layers. The devices exhibit high responsivity, low noise equivalent power, and high specific detectivity.