Monitoring the charge-transfer process in a Nd-doped semiconductor based on photoluminescence and SERS technology

Shuo Yang,Mingyue Hu,Donglai Han,Yingnan Quan,Jinghai Yang,Rui Su,Ming Gao,Jiacheng Yao

doi:10.1038/s41377-020-00361-0

Abstract

Surface-enhanced Raman scattering (SERS) and photoluminescence (PL) are important photoexcitation spectroscopy techniques; however, understanding how to analyze and modulate the relationship between SERS and PL is rather important for enhancing SERS, having a great effect on practical applications. In this work, a charge-transfer (CT) mechanism is proposed to investigate the change and relationships between SERS and PL. Analyzing the change in PL and SERS before and after the adsorption of the probe molecules on Nd-doped ZnO indicates that the unique optical characteristics of Nd3+ ions increase the SERS signal. On the other hand, the observed SERS can be used to explain the cause of PL background reduction. This study demonstrates that modulating the interaction between the probe molecules and the substrate can not only enhance Raman scattering but also reduce the SERS background. Our work also provides a guideline for the investigation of CT as well as a new method for exploring fluorescence quenching.

Highlights

1234567890():,; 1234567890():,; 1234567890():,; 1234567890():,; Introduction Surface-enhanced Raman scattering (SERS), as a powerful spectral technology, has been widely used in the fields of chemistry, pharmaceuticals, biosensors, food detection, and environmental monitoring owing to its high sensitivity and fast response[1,2,3]
The other is the chemical mechanism, which mainly originates from the charge transfer (CT) between adsorbed molecules and SERS-active substrates[5]
In the case of an increase in the PL of Nd-doped ZnO, the inability of the substrate to reduce the PL signal via CT is responsible for the SERS background enhancement

Summary

Introduction

Surface-enhanced Raman scattering (SERS), as a powerful spectral technology, has been widely used in the fields of chemistry, pharmaceuticals, biosensors, food detection, and environmental monitoring owing to its high sensitivity and fast response[1,2,3]. ZnO (Zn1 − xNdxO) as a SERS substrate in which Nd doping was performed using a simple chemical method. We found that both Nd3+ ions and probe molecule fluorescence quenching promote CT, enhance the SERS

Results

Conclusion