高压调控手性二维钙钛矿光学性质

Tuning the optical properties of chiral two-dimensional perovskites by high pressure

手性二维钙钛矿是一类具有非中心对称结构的低维钙钛矿材料,兼具低维钙钛矿和手性材料的优点,可用于产生非线性光学效应。通过高压技术可以实现低维钙钛矿各种光学性质的调控,然而目前对手性二维钙钛矿高压光学性质,特别是高压下非线性光学效应的研究则鲜有报道。利用金刚石对顶砧技术研究了高压对手性二维钙钛矿材料(R-,S-)ClPEA2PbI4的PL光谱、吸收光谱和二次谐波效应的影响。结果表明,随着压强的增大,材料的PL光谱强度先增大到1 GPa的峰值,随后逐渐减弱直至6 GPa左右消失,同时峰值波长507 nm红移到568 nm。高压吸收谱表明手性钙钛矿在6 GPa附近吸收边存在突变。高压下激光二次谐波信号强度随压强的增大而逐渐减小,在6 GPa附近明显减弱。这些结果表明高压是一种调控二维手性钙钛矿光学性质的有效手段,对其未来在发光和近红外频率转换等器件中的应用提供了基础。

Chiral two-dimensional perovskites are a class of low-dimensional perovskite materials with noncentrosymmetric structures.It combines the advantages of low-dimensional perovskites and chiral materials and thus can be used to produce nonlinear optical effects.Various optical properties of low-dimensional perovskites have been reported to be regulated by high-pressure technology.However,there are few reports on the high-pressure optical properties of chiral two-dimensional perovskites,especially the nonlinear optical effect under high pressure.The PL spectrum,absorption spectrum and second harmonic effect(SHG) of a high-pressure chiral two-dimensional perovskite material(R-,S-)ClPEA2PbI4 were studied by the diamond anvil cell technique.The results show that with increasing pressure,the PL spectral intensity of the material first increases to a peak of1 GPa and then decreases gradually until it disappears at approximately 6 GPa,and the peak wavelength shifts from 507 nm to 568 nm.The high-pressure absorption spectra show that there is a sudden change in the absorption edge of the chiral perovskite at approximately 6 GPa,indicating the occurrence of a phase transition.Under high pressure,the intensity of the laser second harmonic signal decreases gradually with increasing pressure and significantly changes near a pressure of 6 GPa.These results show that high pressure is an effective way to regulate the optical properties of two-dimensional chiral perovskites,which provides a basis for their future applications in luminescence,near-infrared frequency conversion and other devices.