The world is going green. Sustainable technologies, such as renewable energy and electric vehicles, are increasingly becoming part of our daily life. This dissertation fills the ensuing gap by providing an insight into the emerging German greentech industry, one of the largest in the world. It develops an integrated and interdisciplinary theoretical framework in which to assess the relationships between innovation, growth and financing from a firm-level perspective; it then tests this framework empirically. In essence, the study finds that: (1) Innovative activity and corporate growth depend heavily on the availability of capital. At the same time, it appears that particularly innovative firms are more likely to face financial constraints. (2) A lack of funds is very apparent for around a quarter of the firms investigated and seems most severe in the early part of the growth state, where firms focus on commercializing existing products. (3) Government support programs only partially offset these effects?