Tuning the light emission of a Si micropillar quantum dot light-emitting device array with the strain coupling effect

Abstract Using an optical signal to realize sensing of a strain signal is a promising application for tactile sensors. However, most research is now focused on piezophototronic LED arrays, which are difficult to incorporate into the Si-based semiconductor industry. Due to the poor photoelectric performance of Si-based devices caused by the indirect band gap of Si, it has always been challenging to construct high density light-emitting devices with Si. Here, a Si-based quantum dot light-emitting device (QLED) array composed of p-Si micropillars is designed and fabricated, and the mechanism for modulation of the strain coupling effect in Si on the electroluminescence performance of Si-based QLEDs is studied. The introduction of QDs easily provides efficient and adjustable light emission and meets the requirements of different practical applications. The emission intensity of the QLED depends on the injected current density, and the transportation processes of the carriers can be modulated by the strain coupling effect. The combination of Si-based photonic devices with pressure sensing may have a significant impact on the fields of electronic skin and human‒machine interfaces. More importantly, this technology is fully compatible with the dominant Si-based semiconductor industry. Therefore, it shows promise in realizing the integration of large-scale Si-based photonic devices and expanding their application fields.