A Study of the Preparation and Properties of Antioxidative Copper Inks with High Electrical Conductivity.

Tsun-Neng Yang,Wei-Chen Chang,Cheng-Huan Chung,Chia-Yang Tsai,Guan-Lin Chen,Jun-Xiang Liang,Wei-Yang Ma

doi:10.1186/s11671-015-1069-y

Abstract

Conductive ink using copper nanoparticles has attracted much attention in the printed electronics industry because of its low cost and high electrical conductivity. However, the problem of easy oxidation under heat and humidity conditions for copper material limits the wide applications. In this study, antioxidative copper inks were prepared by dispersing the nanoparticles in the solution, and then conductive copper films can be obtained after calcining the copper ink at 250 °C in nitrogen atmosphere for 30 min. A low sheet resistance of 47.6 mΩ/□ for the copper film was measured by using the four-point probe method. Importantly, we experimentally demonstrate that the electrical conductivity of copper films can be improved by increasing the calcination temperature. In addition, these highly conductive copper films can be placed in an atmospheric environment for more than 6 months without the oxidation phenomenon, which was verified by energy-dispersive X-ray spectroscopy (EDS). These observations strongly show that our conductive copper ink features high antioxidant properties and long-term stability and has a great potential for many printed electronics applications, such as flexible display systems, sensors, photovoltaic cells, and radio frequency identification.

Highlights

In the past few years, conductive inks have attracted considerable attention due to their growing application in electrodes of silicon-crystal solar cells [1] and the printed electronics industry, such as smart labels [2], flexible displays [3, 4], and radio frequency identification (RFID) [5, 6]
Solvent Proportion After preparing the copper ink, the conductive copper film applied on the glass substrate can be obtained using the copper ink with a calcination process
We can see that the copper film shows no conductivity at a calcination temperature of 200 °C, because copper nanoparticles were melted slightly and cannot form the connections when the calcination temperature is 200 °C or at even lower temperatures

Summary

Introduction

In the past few years, conductive inks have attracted considerable attention due to their growing application in electrodes of silicon-crystal solar cells [1] and the printed electronics industry, such as smart labels [2], flexible displays [3, 4], and radio frequency identification (RFID) [5, 6]. The high price and scarcity of such material limit wide industrial applications [9]. Copper is a good alternative material for silver because of its high electrical conductivity and low price. These advantages could be highly beneficial for the reduction of the manufacturing cost.

Methods

Results

Conclusion