Photovoltaic neurointerface based on aluminum antimonide nanocrystals

Light activated modulation of neural activity is an emerging field for the basic investigation of neural systems and development of new therapeutic methods such as artificial retina. Colloidal inorganic nanocrystals have great potential for neural interfaces due to their adjustable optoelectronic properties via high-level structural, compositional, and size control. However, toxic heavy metal content (e.g., cadmium, mercury), electrochemical coupling to the cells and low photon-to-current efficiency limit their effective use. Here, we introduce the use of aluminum antimonide (AlSb) nanocrystals as the cell interfacing layer for capacitive neural stimulation in the blue spectrum. We demonstrate successful photostimulation of primary hippocampal neurons below ocular safety limits. In addition, our device shows high biocompatibility in vitro and passive accelerated ageing tests indicate a functional lifetime over 3 years showing their feasible use for chronic implants. We demonstrate that nanocrystal biointerfaces hold high promise for future bioelectronics and protheses. Artificial retinas require materials and devices that can interface with the nervous system. Here, aluminum antimonide colloidal nanocrystals are used as the interfacing layer with a biological medium, showing a fast photoresponse of 55 µs and a suggested operational lifetime of 36 months.