Investigation of enhanced ultraviolet emission from different Ti-capped ZnO structures via surface passivation and surface plasmon coupling

Abstract

Photoluminescent properties from three types of Ti and TiO2 capped ZnO structures have been investigated with different surface/volume ratios. Interestingly, it was found that both of surface passivation and surface plasmon (SP) coupling could affect the enhancements of ultraviolet (UV) emissions in the Ti-capped ZnO, while the enhancement rates of UV emissions via SP coupling were much higher than those via surface-passivation modulation with the increasing surface/volume ratios. Upon the evaluation of the dependence of Purcell factor and electron densities, our results can be well explained through energy transfer between defect-related and SP-coupling emissions.

Annealing effects of Au nanoparticles on the surface-plasmon enhanced p-Si/n-ZnO nanorods heterojunction photodetectors

“…16 Recently, surface plasmon resonance has been employed to increase their performance or efficiency because it allows the coupling of more light into or out of the devices. [17][18][19] The surface plasmon resonance, arising from the metal nanoparticles (NPs)/semiconductor interfaces, is currently being exploited due to its large light trapping and its enhancement in optical field. When the electromagnetic radiation illuminates the metal NPs, it can excite the localized plasma resonances within the particle layer, thereby inducing dipole oscillations in the individual particles, which will enhance the incident electromagnetic field near the particle by orders of magnitude, which will then couple radiatively with the semiconductor layer.…”

Enhanced photoluminescence of nonpolar p-type ZnO film by surface plasmon resonance and electron transfer

“…Thus, realizing high optical quality nonpolar p-type ZnO has become a serious problem. In the past few years, surface modification and surface plasmon (SP) resonance with different metals (Au, Ag, Al, Pt, Zn, Ti) have been proven as an effective means to enhance the band-edge emission of light emitting materials [21][22][23][24][25][26][27]. Moreover, deep level emission has been drastically suppressed by Au and Pt modification due to the matching between the deep level defect state and the Fermi level of metals [28][29][30].…”

Evidence for coupling between exciton emissions and surface plasmon in Ni-coated ZnO nanowires

“…Such SP-mediated emission has recently been demonstrated in ZnO nanostructures coated by various metals (Ag, Au, Ti, Al and Pt) and dramatic enhancement of the NBE emission was observed [8][9][10][11][12]. It should also be possible to realize the SP-exciton coupling in TM capped ZnO NWs as TMs support SP modes at their surfaces.…”