Optical and electrical characteristics of lead-free Cu-based halide perovskites in electrospun polystyrene nanofibers

Abstract

Cesium halide perovskites (CHPs) are highly regarded for their low toxicity and resistance to degradation, positioning them as promising candidates for optoelectronic devices. Incorporating CHPs into polymer matrices has further enhanced their stability, as the polymer's long molecular chains provide effective protection. Herein, we successfully incorporated CHPs into polystyrene (PS) via electrospinning using a post-encapsulation method. In this study, we examined the optical and electrical characteristics of CHPs–PS nanofibers with PS concentrations of 5 wt% and 25 wt%. The encapsulation of CHPs into the PS matrix enhances the absorption intensity and influences the emitted PL intensity, with higher PS concentrations resulting in reduced intensity due to the complete coverage of CHPs by the PS. In this study, CHPs–PS nanofibers also exhibit photoluminescence (PL) decay with a fast component (τ₁) of up to 3 ns and an average decay time τ_avg of approximately 100 ns. To the best of our knowledge, CHPs–PS nanofibers exhibit a shorter average decay times (τ_avg) compared to pristine CHPs. The CHPs–PS nanofibers exhibit a tunnelling charge transport mechanism based on the I–V characteristics obtained. The non-linear I–V curves are attributed to the formation of a Schottky barrier, a potential barrier created at the metal–semiconductor interface when the two are connected. The findings of this study provide valuable insights into the development of CHP-incorporated polymer nanofibers, offering promising potential for applications in optoelectronic devices with exceptional optical and electrical characteristics.