This paper describes highlights of exploratory research into next-generation photovoltaic (PV) technologies funded by the United States Department of Energy (DOE) through its National Renewable Energy Laboratory (NREL) for the purpose of finding disruptive or 'leap frog' technologies that may leap ahead of conventional PV in energy markets. The most recent set of 14 next-generation PV projects, termed Beyond the Horizon PV, will complete their third year of research this year. The projects tend to take two notably different approaches: high-efficiency solar cells that are presently too expensive, or organic solar cells having potential for low cost although efficiencies are currently too low. We will describe accomplishments for several of these projects.