标题： 手性从手性钙钛矿通过电荷转移态转移到分子掺杂剂 显示英文标题

标题： Chirality transfer from chiral perovskite to molecular dopants via charge transfer states

摘要： 手性钙钛矿是具有对称性破缺的新兴半导体材料，能够选择性地吸收和发射圆偏振光。然而，大多数手性钙钛矿通常是低维结构，其电导率有限，且其光吸收发生在紫外区域。在本工作中，我们发现将2,3,5,6-四氟-7,7,8,8-四氰基喹二甲烷（F4TCNQ）掺杂到手性钙钛矿基质中，可以通过新兴的电荷转移电子态提高电导率并增加可见光吸收。新的吸收特性表现出从手性基质适应的强圆二色性，这表明通过电子耦合，手性从主体转移到了客体。电荷转移态通过瞬态吸收光谱和理论建模得到了验证。量子化学建模确定了在紧密堆积晶体构型中，客体-主体电子和空穴之间有强烈的波函数重叠，形成了电荷转移吸收态。随后，我们将掺杂的手性钙钛矿薄膜集成到光电探测器中，并展示了在紫外和可见范围内对圆偏振光的选择性检测。我们的结果表明，这是一种向手性基质引入可见光吸收态的通用方法，以拓宽光学活性范围并增强导电性。 显示英文摘要

摘要： Chiral perovskites are emerging semiconducting materials with broken symmetry that can selectively absorb and emit circularly polarized light. However, most of the chiral perovskites are typically low-dimensional structures with limited electrical conductivity and their light absorption occurs in the UV region. In this work, we find doping 2,3,5,6-Tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) in the chiral perovskite matrix can improve the electrical conductivity with an addition of visible light absorption through the emerging charge-transfer electronic states. The new absorption feature exhibits strong circular dichroism adapted from the chiral matrix, which is indicative of a chirality transfer from the host to the guest via an electronic coupling. The charge transfer state is validated by transient absorption spectroscopy and theory modeling. Quantum-chemical modeling identifies a strong wave function overlap between an electron and a hole of the guest-host in a closely packed crystal configuration forming the charge-transfer absorption state. We then integrate the doped chiral perovskite film in photodetectors and demonstrate a selective detection of circularly polarized light both in the UV and visible range. Our results suggest a universal approach of introducing visible photo absorption states to the chiral matrix to broaden the optical active range and enhance the conductivity.