Universidad Politécnica de Madrid

Instituto de energía solar

Novel materials and solar cell concepts


This line aims at researching in the latest frontiers of photovoltaic (PV) energy conversion. Under this line, novel solar cell concepts are analyzed at fundamental level at the time feasible ways for their practical implementation are investigated. Some of these novel concepts, such as the intermediate band solar cell (IBSC) and the three terminal heterojunction bipolar transistor solar cell (3T-HBTSC) originated at our Group.

The need for studying the practical implementation of these novel concepts have triggered, for example, the development of quantum mechanical calculation tools for the prediction of suitable intermediate band materials, the development of a versatile solar cell characterization (IBLAB) and solar cell manufacturing laboratory and the development of modelling tools to compare experimental results with theoretical predictions.

Our semiconductor manufacturing capabilities include a molecular beam epitaxy (MBE) reactor.

Our characterization tools include a unique quantum efficiency setup capable of measuring the absolute quantum efficiency of solar cells at cryogenic temperatures when illuminated simultaneously with two light sources and a solar cell characterization system under concentrated light, capable of reaching up to 10,000 suns also for small area solar cells kept at cryogenic temperatures. These setups pioneered the demonstration of the operation principles of IBSCs.   

Under this line we also study topics such as the limiting efficiency of photovoltaic energy conversion, the role of photon recycling in PV conversion and the application of novel light management approaches to increase the absorption of light in solar cells.