Spin-Selective Charge Transport in Lead-Free Chiral Perovskites: The Key towards High-Anisotropy in Circularly-Polarized Light Detection

A pair of zero-dimensional lead-free chiral perovskites is introduced towards the detection of circularly polarized light (CPL). Although spin-polarized carriers are generated in the perovskites under the CPL, the absorption anisotropy remained low leading to mostly similar density of photo-generated carriers under the two CPLs. Interestingly, due to the intrinsic chirality in the perovskites, they exhibited chirality-induced spin-selectivity (CISS) allowing the transport of only one type of spin-half states. A high anisotropy in photocurrent along the out-of-plane direction has therefore appeared resulting in a spin-dependent photovoltaic effect in vertical heterojunction devices and making them suitable for CPL detection. While a self-powered CPL detector showed a limited (but one of the highest to date) anisotropy factor of 0.3 due to possible spinflips during the transport process, the factor rose to 0.6 under bias prompting extension of the effective spin-diffusion length.

Automated summary

A pair of zero-dimensional lead-free chiral perovskites is introduced for the detection of circularly polarized light (CPL). Due to the intrinsic chirality, these perovskites exhibit chirality-induced spin-selectivity, making them suitable for CPL detection. Although the self-powered CPL detector shows a limited anisotropy factor, the factor increases under bias.