The efficiency of thin film solar cells with large optical band gaps, such as organic bulk heterojunction or amorphous silicon solar cells, is limited by their inability to harvest the infra red part of the solar spectrum. Photochemical upconversion based on triplet amp; 8722;triplet annihilation TTA UC can potentially boost those solar cells by absorbing sub bandgap photons and coupling the upconverted light back into the solar cell in a spectral region that the cell can efficiently convert into electrical current. In the present study we augment two types of organic solar cells and one amorphous silicon a Si H solar cell with a TTA upconverter, demonstrating a solar cell photocurrent increase of up to 0.2 under a moderate concentration 19 suns . The behavior of the organic solar cells, whose augmentation with an upconverting device is so far unreported, is discussed in comparison to a Si H solar cells. Furthermore, on the basis of the TTA rate equations and optical simulations, we assess the potential of TTA UC augmented solar cells and highlight a strategy for the realization of a device relevant current increase by TTA upconversion