Combined information display and information input device

A combined information display and information input device comprising a matrix of independently addressable light emitting devices and a plurality of light sensing devices, said light emitting devices comprising organic light emitting diodes comprising organic light emitting material positioned between a low work function electrode formed from a low work function material layer and a high work function electrode formed from a high work function material layer, and said light sensing devices comprising organic photovoltaic devices comprising at least an organic electron donor and at least an organic electron acceptor positioned between a high work function electrode formed from a high work function material layer and a low work function electrode formed from a low work function material layer, wherein the light emitting devices and the light sensing devices are disposed on a common substrate, and the high work function electrode of both the light emitting devices and the light sensing devices is formed from the same high work function layer and/or the low work function electrode of both the light emitting devices and the light sensing devices is formed from the same low work function layer.