The poor light absorption of visible light for Cs4PbBr6 nanocrystals (NCs) has severely impeded their practical applications. Although the semiconductor/perovskite heterostructure holds great promise for enhancement in absorption, it has remained a serious challenge for synthesizing a semiconductor/perovskite heterostructure. In this work, monodispersed Janus heterostructures composed of Cs4PbBr6 decorated with either multiple Ag or single Ag on its surface (named as mAg/Cs4PbBr6 and sAg/Cs4PbBr6 respectively), are successfully prepared. The size of Ag seeds has an important effect on the shape of the products. Small-sized Ag seeds lead to the formation of mAg/Cs4PbBr6 Janus NCs, while relatively large-sized Ag seeds produce sAg/Cs4PbBr6 Janus NCs. It is noted that this work not only provides a novel method for the modification of individual Cs4PbBr6 NCs, but also enhances the absorption of the Cs4PbBr6 in the visible region, indicating great potential for optoelectronic applications, such as photocatalysis and solar cells.

中文翻译：

---

Ag/Cs4PbBr6 Janus 纳米粒子的形控合成

Cs4PbBr6 纳米晶 (NCs) 对可见光的弱吸收严重阻碍了它们的实际应用。尽管半导体/钙钛矿异质结构在增强吸收方面具有很大的前景，但合成半导体/钙钛矿异质结构仍然是一个严峻的挑战。在这项工作中，成功制备了由表面装饰有多个 Ag 或单个 Ag 的 Cs4PbBr6 组成的单分散 Janus 异质结构（分别命名为 mAg/Cs4PbBr6 和 sAg/Cs4PbBr6）。银晶种的大小对产品的形状有重要影响。小尺寸的 Ag 种子导致 mAg/Cs4PbBr6 Janus NC 的形成，而相对大尺寸的 Ag 种子产生 sAg/Cs4PbBr6 Janus NC。