High-efficiency optical terahertz modulation of organometallic halide perovskite nanoplates on silicon

Abstract An active high-efficiency optical broadband terahertz (THz) modulator was fabricated from organometallic halide perovskite (CH3NH3PbBr3, MAPbBr3) nanoplates on a silicon (Si) substrate. Broadband modulation of THz transmission at a modulation depth of 80% was demonstrated with a photoexcitation power of 3 W/cm2. The aggregation of carriers at the interface of the hybrid structure led to strong THz absorption. The modulation rate reached 80 kHz. The CH3NH3PbBr3 nanoplate/Si device had a higher modulation depth and a similar modulation rate as a bare silicon THz modulator. The results realized a strategy to alleviate the tradeoff between high modulation depth and modulation speed in contrast to bare surfaces and organic films on Si.