Origin and Quenching of Novel ultraviolet and blue emission in NdGaO3: Concept of Super-Hydrogenic Dopants.

Siddhartha Ghosh ,Zhiqi Liu,Ting Yu,T Venkatesan,Chuan Beng Tay,Soo Jin Chua,Yao Cai,Jianqiang Chen,Surajit Saha,Weiming Lü,Saurav Prakash,Zhen Huang,Mark Asta,Abhijeet Patra,Ariando Ariando ,N.l Yakovlev ,Surani Bin Dolmanan ,Tara Datt Bhatt ,Chunxiao Cong ,M Motapothula ,Huang Xiao ,S Tripathy

doi:10.1038/srep36352

Abstract

In this study we report the existence of novel ultraviolet (UV) and blue emission in rare-earth based perovskite NdGaO3 (NGO) and the systematic quench of the NGO photoluminescence (PL) by Ce doping. Study of room temperature PL was performed in both single-crystal and polycrystalline NGO (substrates and pellets) respectively. Several NGO pellets were prepared with varying Ce concentration and their room temperature PL was studied using 325 nm laser. It was found that the PL intensity shows a systematic quench with increasing Ce concentration. XPS measurements indicated that nearly 50% of Ce atoms are in the 4+ state. The PL quench was attributed to the novel concept of super hydrogenic dopant (SHD)”, where each Ce4+ ion contributes an electron which forms a super hydrogenic atom with an enhanced Bohr radius, due to the large dielectric constant of the host. Based on the critical Ce concentration for complete quenching this SHD radius was estimated to be within a range of 0.85 nm and 1.15 nm whereas the predicted theoretical value of SHD radius for NdGaO3 is ~1.01 nm.

Highlights

In this study we report the existence of novel ultraviolet (UV) and blue emission in rare-earth based perovskite NdGaO3 (NGO) and the systematic quench of the NGO photoluminescence (PL) by Ce doping
In this paper we report the origin of room-temperature ultraviolet (UV) and blue emission in NdGaO3 (NGO) bulk systems and the subsequent quench of PL by Ce4+ doping in the place of Nd3+ ions in NGO as a case study of super-hydrogenic dopant (SHD)
We report for the first time ultraviolet (UV) and blue emission in NGO single crystals and poly-crystalline bulk samples obtained by the excitation of a 325 nm laser

Summary

Introduction

In this study we report the existence of novel ultraviolet (UV) and blue emission in rare-earth based perovskite NdGaO3 (NGO) and the systematic quench of the NGO photoluminescence (PL) by Ce doping. In this study we report a novel electronic doping strategy via super-hydrogenic dopants in oxides which can be a very interesting approach for fundamental understanding as well as potential applications. In addition to our current study involving NdGaO3 (NGO), this novel approach can be utilized to study other exotic materials like rare-earth oxides (mostly with R2O3 formula) which exhibit large band-gap, high dielectric constant with potential applications in electronic and photonic technologies. In this paper we report the origin of room-temperature ultraviolet (UV) and blue emission in NdGaO3 (NGO) bulk systems and the subsequent quench of PL by Ce4+ doping in the place of Nd3+ ions in NGO as a case study of super-hydrogenic dopant (SHD)

Methods

Results

Conclusion