Measurement of Reduced Elastic Modulus of Organic Semiconductor Materials for Flexible Organic Light Emitting Diode

Abstract

Reduced elastic moduli of organic luminescent materials deposited onto a glass substrate have been measured by nano-indentation techniques. As a result, it could be observed that the reduced modulus of Alq₃, α-NPD, and the mixed thin films of Alq₃ and NPD are around 12.5–14.0 GPa. Furthermore, the reduced modulus of IZO was around 116 GPa, comparable to that of ITO. In addition, the relationship between stress and strain has been discussed by assuming that the relationship follows a power law. These fundamental data obtained will be applied to the design of flexible organic light emitting diodes (OLEDs) and production equipment using roll-to-roll process.