Organic indoor PV: vanishing surface recombination allows for robust device architecture

As a promising candidate to drive low-power, off-grid applications, organic indoor photovoltaics are beginning to attract research attention. In organic photovoltaic devices, charge transport layers are often used to promote the extraction of majority carriers while blocking minority carriers. They can however be a source of device degradation and introduce additional complexity to the fabrication of the device stack. Here, a simplified, yet performant indoor OPV architecture with extended absorber thickness, but without electron transport layer (ETL) is demonstrated. We show that the diminished impact of the ETL on indoor OPV results from a drastically reduced surface recombination in thick absorber devices. The proposed simplified device architecture with thick absorber has great potential in large-scale production.