鈣鈦礦微米管於介電質與金屬層上之光激螢光研究

Abstract

Organic-inorganic halide perovskites can grow into different structures including films and microscale cavities through different processing condition. Furthermore, halide perovskites with long carrier lifetimes and diffusion lengths are emerging as one of the most promising materials for photovoltaic technology. These properties along with high fluorescence yield and tunable wavelength make halide perovskites ideal materials for LED and lasing. Besides, perovskite has efficient optical gain and amplified spontaneous emission at strikingly low thresholds. Therefore, halide perovskites might be ideal candidates for construction of high-performance lasers. In this work, we present the study of optical emission properties carried out on methylammonium lead triiodide perovskites (CH3NH3PbI3) films and its micro-scale structures. In particular, we were interested in the influence of surface plasmonic coupling on the emission from these microtubes so that the time-integrated and time-resolved photoluminescence (PL) was measured for CH3NH3PbI3 microtubes fabricated on metal (Al and Ag) film with 5 nm-thick SiO2 spacer layer. Underlying metal films enhances the intensity of PL, but when a thin spacer layer is grown between metal film and microtubes, the PL from microtubes coupled with Al film enhances, while that from tubes with Ag film significantly quenches. We attribute the PL enhancement to surface plasmon resonance whereas the quench to nonradative Förster energy transfer which is significant for Ag. In the temperature dependent measurement, we observed different value of thermal coefficient for film and micro structures. We found that internal quantum efficiency η_int of micro long tube and short tube with metal film increase and this is due to surface plasmon coupling. With SiO2 spacer layer on Al film, internal quantum efficiency η_int of micro long tube further increases. Due to high binding energy along with highest internal quantum efficiency η_int of our samples, micro long tube with SiO2 spacer layer on Al is best candidate for light emitting material. From the analysis of the bandwidth of PL, we observed that the Fro ̈hlich interaction between carrior and LO phonons provides the dominant contribution to the predominantly homogeneous linewidth broadening in these perovskites at room temperature.

Organic-inorganic halide perovskites can grow into different structures including films and microscale cavities through different processing condition. Furthermore, halide perovskites with long carrier lifetimes and diffusion lengths are emerging as one of the most promising materials for photovoltaic technology. These properties along with high fluorescence yield and tunable wavelength make halide perovskites ideal materials for LED and lasing. Besides, perovskite has efficient optical gain and amplified spontaneous emission at strikingly low thresholds. Therefore, halide perovskites might be ideal candidates for construction of high-performance lasers. In this work, we present the study of optical emission properties carried out on methylammonium lead triiodide perovskites (CH3NH3PbI3) films and its micro-scale structures. In particular, we were interested in the influence of surface plasmonic coupling on the emission from these microtubes so that the time-integrated and time-resolved photoluminescence (PL) was measured for CH3NH3PbI3 microtubes fabricated on metal (Al and Ag) film with 5 nm-thick SiO2 spacer layer. Underlying metal films enhances the intensity of PL, but when a thin spacer layer is grown between metal film and microtubes, the PL from microtubes coupled with Al film enhances, while that from tubes with Ag film significantly quenches. We attribute the PL enhancement to surface plasmon resonance whereas the quench to nonradative Förster energy transfer which is significant for Ag. In the temperature dependent measurement, we observed different value of thermal coefficient for film and micro structures. We found that internal quantum efficiency η_int of micro long tube and short tube with metal film increase and this is due to surface plasmon coupling. With SiO2 spacer layer on Al film, internal quantum efficiency η_int of micro long tube further increases. Due to high binding energy along with highest internal quantum efficiency η_int of our samples, micro long tube with SiO2 spacer layer on Al is best candidate for light emitting material. From the analysis of the bandwidth of PL, we observed that the Fro ̈hlich interaction between carrior and LO phonons provides the dominant contribution to the predominantly homogeneous linewidth broadening in these perovskites at room temperature.