A large number of health problems, such as diabetes, hearing loss and retinal degeneration, can be cured by stimulation of neurons. One of the effective strategies for neural stimulation is through light-induced photoactive surfaces owing to the non-invasive and remotely accessible characteristics of light. Quantum dots are suitable candidate for such applications due to their absorption of visible light, bandgap tunability through quantum confinement effect and ease of integration into device structures due to their nanoscale size. In this study, we show that proper engineering of quantum dot nanostructure and band alignment of optoelectronic biointerface allow for bidirectional optical stimulation of neurons with high level control on stimuli strength.
Colloidal quantum dots (QDs) are intriguing materials due to their outstanding properties like spectral tunabilty, high quantum efficiency, narrow emission spectra and solution processability. Many past and on-going researches on quantum dot light-emitting devices (QLEDs) have led to achieving efficiency levels comparable to organic LEDs and semiconductor LEDs. However, most QLED studies are based on toxic QDs, which raises concerns about environmental and health issues. Our study demonstrates the application of a new non-toxic nanomaterial, InP/ZnO QDs, to LEDs. Integrating InP/ZnO QDs into device architecture, we produced low turn-on voltage (2.8 V), saturated color devices, which have luminance levels (600 cd/m2) suitable for display technology.