abstract
In this contribution, we first give a brief historical overview of the recent developments on polymer/silicon heterojunction cells. We then focus on our most recent results concerning: (i) the PEDOT:PSS/c-Si interface design, where the thickness of the native oxide in-between the c-Si surface and the polymer is shown to play a crucial role, (ii) a new type of heterojunction cell, where the hole-selective layer is PEDOT:PSS and the electronselective layer is well-passivating phosphorus-doped amorphous silicon (n-a-Si:H), (iii) the stability of the polymer/silicon cells in ambient environment. We demonstrate for the first time that the efficiencies of BackPEDOT cells are long-term stable if a metal foil is used as rear metallization scheme, as the metal foil does not transmit any humidity in contrast to evaporated metals. (iv) We present first results of our attempt to implement a PEDOT:PSS/c- Si junction into an industrial-type large-area (15.6×15.6 cm2) screen-printed c-Si solar cell and reach an efficiency of 19.5% in our first batch of cells.