红外与毫米波学报, 2018, 37 (5): 523, 网络出版: 2018-12-26
太赫兹时间分辨系统研究有机卤化物钙钛矿薄膜的超快太赫兹调制
Ultrafast terahertz modulation characteristics of organolead halide perovskite films revealed by time-resolved terahertz spectroscopy
摘要
研究了利用太赫兹时间分辨系统研究有机卤化物钙钛矿薄膜(CH3NH3PbI3 and CH3NH3PbI3-xClx)的皮秒尺度的超快太赫兹调制特性.在光激发作用下出现了太赫兹透射波的瞬时下降.相比于CH3NH3PbI3薄膜, 在光激发作用下CH3NH3PbI3-xClx薄膜展现了更高的调制深度(10%).通过测算材料的电导率及载流子浓度, 其调制机理为瞬态光激发载流子浓度上升.实验结果表明, CH3NH3PbI3-xClx薄膜可作为一种高效超快太赫兹调制器件.
Abstract
Ultrafast terahertz (THz) modulation characteristics of organolead halide perovskite films (CH3NH3PbI3 and CH3NH3PbI3-xClx) were investigated on picosecond time scales using time-resolved THz spectroscopy. Upon photo-excitation, a transient decrease in THz transmission was observed. Compared with CH3NH3PbI3, CH3NH3PbI3-xClx showed a better modulation depth (10%) within the range of the photo-excitation powers used. The mechanism underpinning this photoconductive ultrafast response was determined by measuring the transmission properties and calculating the carrier density. The larger crystalline bulk of the CH3NH3PbI3-xClx film produced higher carrier densities than the CH3NH3PbI3 film. These results demonstrate that CH3NH3PbI3-xClx films are promising materials for developing high-performance THz modulators and ultrafast switchable THz photoelectric devices.
张波, 吕龙锋, 沈京玲. 太赫兹时间分辨系统研究有机卤化物钙钛矿薄膜的超快太赫兹调制[J]. 红外与毫米波学报, 2018, 37(5): 523. ZHANG Bo, LYU Long-Feng, SHEN Jing-Ling. Ultrafast terahertz modulation characteristics of organolead halide perovskite films revealed by time-resolved terahertz spectroscopy[J]. Journal of Infrared and Millimeter Waves, 2018, 37(5): 523.