Filterless narrowband visible photodetectors

Wavelength selective light detection is crucial for many applications such as imaging and machine vision. Narrowband spectral responses are required for colour discrimination and current systems use broadband photodiodes combined with optical filters. This approach increases architectural complexity, and limits of the quality of colour sensing. Here we report filterless, narrowband red, green, and blue photodiodes with tuneable spectral responses. The devices have simple planar junction architectures with the photoactive layer being a solution processed mixture of either an organohalide perovskite or lead halide semiconductor, and a neutral or cationic organic molecule. The organic molecules modify the optical and electrical properties of the photodiode and facilitate narrowing charge collection narrowing of the device's external quantum efficiency. These red, green, and blue photodiodes all possess full-width-at-half-maxima of <100 nm and performance metrics suitable for many imaging applications