Sacrificial layer-assisted nanoscale transfer printing

Junshan Liu,Liding Wang,Bo Pang,Jinlong Song,Rui Li,Yao Lu,Xiaoguang Hu,Xiaojun Zhao,Dazhi Wang,Riye Xue

doi:10.1038/s41378-020-00195-1

Junshan Liu, Liding Wang + Show 8 more

Open Access

https://doi.org/10.1038/s41378-020-00195-1

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Abstract

Transfer printing is an emerging assembly technique for flexible and stretchable electronics. Although a variety of transfer printing methods have been developed, transferring patterns with nanometer resolution remains challenging. We report a sacrificial layer-assisted nanoscale transfer printing method. A sacrificial layer is deposited on a donor substrate, and ink is prepared on and transferred with the sacrificial layer. Introducing the sacrificial layer into the transfer printing process eliminates the effect of the contact area on the energy release rate (ERR) and ensures that the ERR for the stamp/ink-sacrificial layer interface is greater than that for the sacrificial layer/donor interface even at a slow peel speed (5 mm s−1). Hence, large-area nanoscale patterns can be successfully transferred with a yield of 100%, such as Au nanoline arrays (100 nm thick, 4 mm long and 47 nm wide) fabricated by photolithography techniques and PZT nanowires (10 mm long and 63 nm wide) fabricated by electrohydrodynamic jet printing, using only a blank stamp and without the assistance of any interfacial chemistries. Moreover, the presence of the sacrificial layer also enables the ink to move close to the mechanical neutral plane of the multilayer peel-off sheet, remarkably decreasing the bending stress and obviating cracks or fractures in the ink during transfer printing.

Highlights

Transfer printing is capable of transferring various classes of materials with a wide range of geometries and configurations from one substrate to another via a stamp and has been extensively used for flexible and stretchable electronics[1], such as bendable transistors[2], stretchable nanophotonic devices[3], stretchable radio frequency identification tags[4], and flexible photodetectors[5]
A sacrificial layer is deposited on the surface of a donor substrate, and ink is prepared on the sacrificial layer (Fig. 1a)
The sacrificial layer plays the role of the ink, and the ink is just sandwiched between the sacrificial layer and the stamp

Summary

Introduction

Transfer printing is capable of transferring various classes of materials with a wide range of geometries and configurations (referred to as ink) from one substrate (referred to as the donor) to another via a stamp and has been extensively used for flexible and stretchable electronics[1], such as bendable transistors[2], stretchable nanophotonic devices[3], stretchable radio frequency identification tags[4], and flexible photodetectors[5]. Controlling Gstamp/ink by controlling the peel speed of the stamp from the ink can enable transfer printing to be conducted and has been widely exploited[27,28,29,30]. To our best knowledge, this speed-based transfer printing method has never been used for transferring nanoscale patterns. This is mostly because the ERR is related to the contact area in addition to the peel speed[26,31]. The contact area at the stamp/ink interface is generally considered to be equal to that at the ink/donor interface because it is believed that the flexibility of the stamp can help obtain a conformal contact[27], so the effect of the contact area on the ERR is usually neglected

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Conclusion