This course introduces solar cell and other technologies for low-carbon energy systems. It starts with a review of semiconductors, with a focus on the fundamentals for solar cell development. The content covers such as electron and hole, Fermi energy, generation and recombination, p-n junction, and the optical and optoelectronic properties. The course then elaborates the solar cell technology in-depth – covering (i) the basic principles of photovoltaic devices, including absorption, photo-electric conversion, conversion efficiency, loss mechanism, carrier collection and device characterization; (ii) the four generations of solar cell technology, e.g., monocrystalline solar cells, thin-film solar cells, dye-sensitized solar cells, organic solar cells; and (iii) other related engineering topics such as concentrated solar power, management techniques, manufacturing systems, reliability, life-cycle analysis, markets and policies. Beyond the solar cell technology, the course continues with discussions on other low-carbon energy technologies, for instance, thin-film transistors, ultralow-power flexible electronics, light-emitting diodes, and nanoenergy harvesting technologies. In the end, the course concludes with fabrication towards large-scale, low-cost and green manufacturing, including the key considerations in developing large-scale, flexible devices and the emerging printing techniques.