Cation Exchange Mediated Synthesis and Tuning of Bimodal Plasmon in Alloyed Ternary Cu₃BiS_3–xSe_x Nanorods

Abstract

We report a robust methodology for synthesizing monodisperse alloyed Bi 2 S 3−x Se x nanorods (NRs) to tune optical properties with the variation of Se concentration. The intercalation of Cu(I) into the presynthetic Bi 2 S 3−x Se x NRs converted to ternary Cu 3 BiS 3−x Se x NRs via cation exchange process. The transformation was monitored through the formation of core/shell Bi 2 S 3−x Se x / Cu 3 BiS 3−x Se x nanorod heterostructures. Shape anisotropy results in near-infrared bimodal localized surface plasmon resonance (LSPR) in Cu 3 BiS 3−x Se x nanorod over a broad range from 600 to 3500 nm with increase of Se:S ratio. The LSPR sensitivity, defined as the change in the LSPR peak wavelength per unit change in the refractive index (RI) of the medium, was estimated to be 250−350 nm/RI unit, much higher than other copper chalcogenides like Cu 2 S/Cu 2 Se. A fast photodetector was fabricated by Cu 3 BiS 3−x Se x NRs with high photocurrent gain value (∼125) with Se alloying. The intrinsic Cu vacancies and the effective mass of charge carriers play important roles to manipulate optical and electrical properties of Cu 3 BiS 3−x Se x NRs.

Co-electrodeposition of Cu3BiS3 thin films in weakly alkaline aqueous solutions for photovoltaic application

“…This changing law of E g seems have a relationship with that of Cu/Bi ratio. According to the previous reports [37][38][39][40], the bandgaps of Bi 2 S 3 and Cu 2 S are about 1.8 eV and 1.1 eV, respectively, coincidentally, the bandgap of Cu 3 BiS 3 film decreased exactly as the increase of the Cu/Bi ratio in our research. Therefore, it is a practical method to adjust the E g of the Cu 3 BiS 3 film by changing the Cu/Bi ratio.…”

Heavy‐Metal‐Free Colloidal Semiconductor Nanorods: Recent Advances and Future Perspectives

“…The photocurrent gain (I photon /I dark ) and sensitivity of Bi 2 S 3 NR-based photodetectors can be further improved by incorporation of Se and Cu into Bi 2 S 3 NRs to produce alloyed ternary Cu 3 BiS 3-x Se x NRs. [57] The increase of the Se concentration of Bi 2 S 3 NRs makes the ternary systems more capable in absorbing solar light in the range of 500-1400 nm than the pure Bi 2 S 3 NRs and enhances the photocurrent gain with a high value of ∼125 (Figure 10d-f). The increased photocurrent gain of Cu 3 BiS 3-x Se x NRs is mainly originating from the increased probability of efficient exciton-plasmon coupling.…”

“…The increased photocurrent gain of Cu 3 BiS 3-x Se x NRs is mainly originating from the increased probability of efficient exciton-plasmon coupling. [57] Reproduced with permission. [57] Copyright 2018, American Chemical Society.…”

Insights of Crystal Growth, Nucleation Density, and Shape Modulations in the Formation of I–V–VI Ternary Semiconductor Nanoplatelet Photoelectrocatalysts

“…From the literature reports, it is revealed that while the ternary materials involving In­(III) and Ga­(III) of group III materials are extensively reported for obtaining I–III–VI semiconductor nanocrystals, ,,− metal ions involving group V are less explored. ,,, These group I–V–VI semiconductors have wide composition variable crystal phases ,,,− and also have different reactivities of the involved cations such as Bi and Sb ions. − Hence, wide investigations of the reaction pathways and the formation mechanism are required for designing the high-quality dimension variation of such ternary nanocrystals. Keeping this in mind, insights of the formation mechanism and importance of ternary nucleation leading to the growth of ternary group I–V–VI nanocrystals of Cu 3 BiS 3 is reported.…”