Solution Processing of Hydrogen-Terminated Silicon Nanocrystal for Flexible Electronic Device.

We demonstrate solution processing of hydrogen-terminated silicon nanocrystals (H-Si NCs) for flexible electronic devices. To obtain high and uniform conductivity of a solution-processed Si NC film, we adopt a perfectly dispersed colloidal H-Si NC solution. We show a high conductivity (2 × 10-5 S/cm) of a solution-processed H-Si NC film which is spin-coated in air. The NC film (area: 100 mm2) has uniform conductivity and responds to laser irradiation with 6.8 and 24.1 μs of rise and fall time. By using time-of-flight measurements, we propose a charge transport model in the H-Si NC film. For the proof-of-concept of this study, a flexible photodetector on a polyethylene terephthalate substrate is demonstrated by spin-coating colloidal H-Si NC solution in air. The photodetector can be bent in 5.9 mm bending radius at smallest, and the device properly works after being bent in 2500 cycles.