Fabrication and Electro-optic Properties of MWCNT Driven Novel Electroluminescent Lamp

TL;DR

This paper introduces a cost-effective method using multi-walled carbon nanotubes to enhance electroluminescence in ZnS:Cu phosphor, enabling stable, low-voltage light emission through a novel hybrid material.

Contribution

It presents a new technique combining CNTs with phosphor to achieve efficient electroluminescence at low voltages, with a detailed understanding of the underlying mechanism.

Findings

Enhanced electroluminescence at low voltages

CNTs act as electric field enhancers and facilitate hot carrier injection

Mechanism explained via internal field emission and impact excitation

Abstract

We present a novel, cost-effective and facile technique, wherein multi-walled carbon nano-tubes (CNTs) were used to transform a photoluminescent material to exhibit stable and efficient electroluminescence (EL) at low-voltages. As a case study, a commercially available ZnS:Cu phosphor (P-22G) was combined with a very low concentration of CNTs dispersed in ethanol and its alternating current driven electroluminescence (AC-EL) is demonstrated. The role of CNTs has been understood as a local electric field enhancer and facilitator in the hot carrier injection inside the ZnS crystal to produce EL in the hybrid material. The mechanism of EL is discussed using an internal field emission model, intra-CNT impact excitation and the recombination of electrons and holes through the impurity states.