Stratified optical materials and coatings play an important role in improving the efficiency of solar conversion processes. At present the best-known stratified media are multilayer and graded-index films. Stratified media are used as heat mirrors, selective absorbers, antireflective films, and transparent insulation. Graded-index films can be homogenous materials, spatially oriented structures, or etched materials. Such films and materials improve efficiency and allow for innovation in energy-efficient windows, passive and active energy conversion, and photovoltaics. The horizons of invention can be expanded by considering new materials, techniques, and concepts that can increase the efficiency of energy utilization in buildings and transform solar energy into heat, light and electrical power. The stability requirements for materials to effectively collect and transmit solar energy are extremely demanding. This, coMbined with the need for inexpensive production methods, creates a broad area for innovative scientific research. We describe several approaches and materials systems for two broad application categories: 1) low-conductance, high-transmittance systems and 2) solar absorbers.