Organic semiconductors are conjugated molecular materials with highly tunable electrical and optical functionality. These materials have found wide interest as thin film components in optoelectronic and photovoltaic devices, where attractive physical properties are combined with high throughput processing on mechanically flexible substrates enabling novel device form factors. To date, the most successful application of organic semiconductor thin films has been in displays based on organic light-emitting devices (OLEDs). An OLED consists of a vertical thin film stack deposited via a high vacuum, physical vapor deposition process. While these layers are typically amorphous and glassy, ongoing work has revealed the complexity and tunability in property and performance that can come with active engineering of molecular orientation.