This project proposal intends the upgrade of the Metal Organic Vapour Phase Epitaxy (MOVPE) reactor of the IES-UPM._x000D_ Because of the age of the reactor (around 17 years), most of its components are obsolete, discontinued and without the possibility of an immediate substitution. Therefore, once a failure occurs (what is more and more frequent), a forced stop is prolonged until a repair choice is found. The MOVPE reactor of the IES-UPM is the only one commercial and with significant throughput (3x2 inch or 1x4 inch wafers) existing in Spain._x000D_ The performance of our MOVPE reactor has allowed us to reach the following _x000D_ achievements: a) to achieve projects (including FP7 and H2020) and contracts for more than 8M; b) to achieve a world record efficiency for solar cells which is the only one_x000D_ obtained by a Spanish institution; c) to place the III-V Semiconductors Group among the leaders of multijunction solar cells; d) to publish more than 170 papers of high impact; e) to promote the technology transfer to both Spanish and foreign companies._x000D_ The total price of the reactor, including the required systems of gases, alarms, etc. was around 2M. The upgrade we want to carry out now has a cost of 437,500 and will allow us to use the reactor for at least 10 years. Consequently, with the upgrade of the reactor we want to go further with the aforementioned achievements thanks to the elimination of prolonged stops due to failures and also to a better control and reproducibility of the epis