Highly efficient blue emitting one dimensional lead-free nanocrystals. Issue 31 (21st July 2022)

• Record Type: Journal Article
• Authors: Duan, Jianing; Xi, Jun; Jiao, Bo; Dai, Jinfei; Zu, Yanqing; Wu, Zhaoxin
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 31(2022)
• Page Start: 11323
• Page End: 11328
• Publication Date: 2022-07-21
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2tc01591a
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Cs5 Cu3 Cl6 I2 nanocrystals exhibit a blue light emission with a high PLQY of 73.7%. Multiple self-trapped excitons are proposed to be responsible for the peculiar emission originating from various Cu–Cu interactions on one-dimensional chains. Abstract : Cesium copper halide perovskite-like nanocrystals (NCs) have emerged recently due to their nontoxicity and highly efficient and peculiar optoelectronic properties; however, this field is far from being quested yet. In this study, Cs5 Cu3 Cl6 I2 NCs in a one-dimensional chain structure are proposed by a modified hot injection method for the first time. The as-synthesized highly even Cs5 Cu3 Cl6 I2 NCs yield a blue emission at 464 nm, coupling a high photoluminescence quantum yield (PLQY) of 73.7%. The large Stokes shift of 186 nm and broadband emission demonstrate the existence of self-trapped excitons in Cs5 Cu3 Cl6 I2 NCs under UV excitation. Unlike the zero-dimensional prototype, one-dimensional chains consist of different polyhedron connection fashions, fostering their unique luminescent properties. We found Cs5 Cu3 Cl6 I2 NCs possess an asymmetric PL emission peak prevailing in a broad temperature range, highly correlating to abnormal multiple self-trapped excitons at 2.95 eV, 2.69 eV, and 2.53 eV, respectively. Interrogating the fundamental, triple Cu–Cu interactions originating from various polyhedral connection ways of one-dimensional chains are responsible for the hybrid excitonic states. This work establishes a rising class of lead-free NCs as an eligible candidate for stable functional device application and illustrates the fundamentals underlying the dissimilar excitonic properties of one-dimensional copper halides.