Enhancement of Trap-Assisted Green Electroluminescence Efficiency in ZnO/SiO₂/Si Nanowire Light-Emitting Diodes on Bendable Substrates by Piezophototronic Effect

Abstract

The trap-assisted green electroluminescence (EL) efficiency of a light-emitting diode (LED) consisting of a ZnO nanowire (NW), a SiO2 layer, and a Si NW on a bendable substrate is enhanced by piezophototronic effect. The green EL originates from radiative recombination through deep-level defects such as interstitial zinc, interstitial oxygen, oxygen antisite, and zinc vacancy in the component ZnO NW. The efficiency of the trap-assisted green EL is enhanced by a piezophototronic factor of 2.79 under a strain of 0.006%. The piezoelectric field built up inside the component ZnO NW improves the recombination rate of the electron-hole pairs thereby enhancing the efficiency of the trap-assisted green EL.