Disorder, Defects, and Their Effect on Charge Transport in Organic Semiconductors
Author | : Jonathan Rivnay |
Publisher | : |
Total Pages | : |
Release | : 2011 |
ISBN-10 | : OCLC:768306851 |
ISBN-13 | : |
Rating | : 4/5 (51 Downloads) |
Book excerpt: Understanding the nature of charge transport and its limitations on device performance has guided the rational design of organic semiconductors for over a decade. This understanding has led to the development of high performance small molecule and polymeric semiconductors for applications in low-cost complementary logic circuits, displays, lighting, and solar cells. Unfortunately, the large catalog of available materials and processing variables make it difficult to outline general design rules. Specifically, in polycrystalline and semicrystalline organic semiconductors, little is understood about the structural order within a grain and between grains, and even less is known about how this structure affects the material's performance. In this thesis, characterization methods are introduced to address these issues. To understand the structural source of electronic defects, a multi-step Fourier transform X-ray line shape analysis with thorough error analysis is adapted to determine crystallite size and intra-grain cumulative disorder. For the first time, the intra-crystalline disorder in transport-relevant directions is quantitatively determined for a variety of high performing organic semiconductors. These van der Waals bonded crystallites exhibit a wide range of disorder (from