Materials purity, growth, and patterning

Abstract

This chapter describes the purification and growth of organic materials, device patterning, and coating of large substrate areas using volume manufacturing processes. Organic semiconductors are no different from other electronic materials—purity is of the utmost importance. The chapter begins by describing several purification techniques for achieving and assessing the quality of electronic-grade materials. Next is a discussion of bulk crystal growth, and growth by more technologically important methods for achieving thin films using solution or vapor phase growth processes. Post-growth annealing for achieving desired film morphologies is also discussed. Patterning of device structures by photolithography, stamping and nanoimprint lithography on both planar and curved surfaces are described. This is followed by consideration of manufacturing processes such as roll-to-roll production, and the constraints that such processes place on the choice of substrate. Last, packaging and device encapsulation that maintain substrate flexibility while protecting devices from attack by adverse environments is discussed.