The last decade has witnessed rapid progress in organic photovoltaics boosted by the design and synthesis of novel p-conjugated small donor–acceptor molecules (mainly thiophene-based chromophores) and by the control and optimization of both device processing and fabrication. Although some important progress has been reached, current challenges remain to further improve their efficiency, durability and cost- effectiveness in order to compete with silicon-based solar cells. This review will provide the scientific community with both general and in depth information on the structure–property relationships related to the photocurrent efficiencies comprising detailed I/V characteristics. It will highlight guidelines for designing new efficient and emerging alternatives to conjugated polymers on the basis of thiophenic chromophores representing, to date, the most widely used class of organic materials for such a purpose as well as important information on device processing or fabrication factors that could influence their performances.