Quantum Optoelectronics

Abstract:

This is a micro-photoluminescence(micro-PL) based study to investigate the optical property of surface passivation effect with Pb(OH)2 coated CsPbBr3 micro/nano rods and demonstration of stimulated emission from defect states. We also presented a technique with completely separable excitation and collection in a confocal microscopy. In this work, we have supported with data from time-resolved study, time-integrated PL map and scan with either collection/excitation fixed and scanning the other.

Abstract:

The updated data files are supporting demonstration of weak coupling between a cavity mode and emission from a single quantum dot. In this research (done by January 2020) we developed an easily controlled fabrication process to deterministically write a mode gap cavity over a photonics crystal waveguide. All data files uploaded here are obtained through micro-photoluminescence(PL) experiments. Those associated with 'fig2' are the single time-integrated PL spectra with the first column in the data file being wavelength in 'nm'. fig2 a and b are single PL spectra of high and low density of ensemble quantum dots emission before coating the cavity. fig2 c is showing the crossover between the cavity emission mode and the quantum dot spectrum over a temperature run. fig 3 data is the time-resolved PL data taken at temperatures of 6K and 30K demonstrating Purcell enhancement. The corresponding instrument response function (irf) of the excitation laser signal is also included for deconvolution. NB: This is Version 2 of the data and supercedes Version 1 at https://doi.org/10.5287/bodleian:dXbD81ZmD

Abstract:

The updated data files are supporting demonstration of weak coupling between a cavity mode and emission from a single quantum dot. In this research (done by January 2020) we developed an easily controlled fabrication process to deterministically write a mode gap cavity over a photonics crystal waveguide. All data files uploaded here are obtained through micro-photoluminescence(PL) experiments. Those associated with 'fig4' are the single time-integrated PL spectra with the first column in the data file being wavelength in 'nm'. fig4 a and b are single PL spectra of high and low density of ensemble quantum dots emission before coating the cavity. fig4 c is showing the crossover between the cavity emission mode and the quantum dot spectrum over a temperature run. fig 5 is the time-resolved PL data of three different temperatures demonstrating Purcell enhancement. The corresponding first column represents time and is in the unit of 'ns'.

Abstract:

The updated data files are supporting demonstration of weak coupling between a cavity mode and emission from a single quantum dot. In this research (done by January 2020) we developed an easily controlled fabrication process to deterministically write a mode gap cavity over a photonics crystal waveguide. All data files uploaded here are obtained through micro-photoluminescence(PL) experiments. Those associated with 'fig4' are the single time-integrated PL spectra with the first column in the data file being wavelength in 'nm'. fig4 a and b are single PL spectra of high and low density of ensemble quantum dots emission before coating the cavity. fig4 c is showing the crossover between the cavity emission mode and the quantum dot spectrum over a temperature run. fig 5 is the time-resolved PL data of three different temperatures demonstrating Purcell enhancement. The corresponding first column represents time and is in the unit of 'ns'. NB: This is Version 1 of the data and has been superseded by Version 2 at https://doi.org/10.5287/bodleian:ErJbzzO84

Abstract:

Photocatalytic water splitting is attracting enormous interest for the storage of solar energy but no practical method has yet been identified. In the past decades, various systems have been developed but most of them suffer from low activities, a narrow range of absorption and poor quantum efficiencies (Q.E.) due to fast recombination of charge carriers. Here we report a dramatic suppression of electron-hole pair recombination on the surface of N-doped TiO2 based nanocatalysts under enhanced concentrations of H+ and OH−, and local electric field polarization of a MgO (111) support during photolysis of water at elevated temperatures. Thus, a broad optical absorption is seen, producing O2 and H2 in a 1:2 molar ratio with a H2 evolution rate of over 11,000 μmol g−1 h−1 without any sacrificial reagents at 270 °C. An exceptional range of Q.E. from 81.8% at 437 nm to 3.2% at 1000 nm is also reported.