DOI: 10.5281/zenodo.7419322
title: Protected ultrathin cuprous oxide film for photocatalysis: Excitation and relaxation dynamics

description: The main data analysis was done with Wavemetrics Igor Pro 7.08 using user-defined macros. Data files given in *.itx<br> format are human-readable text files that can be opened in Igor Pro. User-defined macros are available from the<br> authors upon reasonable request. Static spectra are measured with the proprietary "Croissant" software for the<br> channeltron analyzer and saved in human-readable *.plsp format, or SpecsLab Prodigy 4.60.1 for the 2D analyzer and<br> saved in the proprietary SPECS *.sle format or exported into *.itx format. Time-resolved spectra are measured with a<br> proprietary LabView program and exported in the binary HDF5 *.h5 file format. <br> ******************************************** Fig. 1 LEED and He Ia ARPES ********************************************<br> LEED images taken with SBIG STF-8300 CCD Camera, the SBIG format is a 16-bit grayscale bitmap with metadata.<br> Fig. 1a: LEED image at 120 eV<br> LEED220210_120eV_Cu111_hBN_Cu2O.SBIG<br> Fig. 1b: LEED image at 48 eV<br> LEED220210_048eV_Cu111_hBN_Cu2O.SBIG other energies (not shown in the figure): see Fig. S2/S3 Fig. 1c: He Ia spectrum second derivative as function of parallel momentum and binding energy<br> Spectra measured with VG ESCALAB 220 channeltron hemispherical analyzer by tilting the sample at two fixed azimuthal<br> angles and using a Gammadata VUV 5050 monochromated helium lamp. The azimuthal angles correspond to the M and K<br> directions, respectively, as determined by x-ray photoelectron diffraction of the Cu(111) surface. Measurement<br> parameters are given in the files.<br> Positive parallel momentum: M direction, VG2Z220628N015.plsp<br> Negative parallel momentum: K direction, VG2Z220628N016.plsp<br> Combined ARPES spectrum as a function of parallel momentum and binding energy: VG2Z220628N015_N016.itx<br> Second derivative along energy direction: VG2Z220628N015_N016d.itx; smoothed: VG2Z220628N015_N016d_smth.itx <br> ************************************************ Fig. 2 He IIa ARPES ************************************************<br> All ARPES spectra measured with SPECS Phoibos 150 WAL hemispherical analyzer (2D detector) using SpecsLab Prodigy<br> software and non-monochromated helium lamp. Fig. 2a: Detail of He IIa spectrum measured on h-BN/Cu(111)<br> Full angle-resolved spectrum (intensity as function of angular coordinate and kinetic energy), summed over all energy<br> channels and scans, exported from SpecsLab Prodigy as Igor Text. All measurement parameters are given in the file.<br> Spectrum HeIIa h-BN Cu111 20201023.itx<br> Spectrum scale converted into parallel momentum and binding energy: Spectrum HeIIa h-BN Cu111 20201023 k2.itx Fig. 2b: Detail of He IIa spectrum measured on h-BN/Cu2O/Cu(111)<br> Full angle-resolved spectrum (intensity as function of angular coordinate and kinetic energy), summed over all energy<br> channels and scans, exported from SpecsLab Prodigy as Igor Text. All measurement parameters are given in the file.<br> Spectrum HeIIa h-BN Cu2O Cu111 20220211.itx<br> Spectrum scale converted into parallel momentum and binding energy: Spectrum HeIIa h-BN Cu2O Cu111 20220211 k2.itx Fig. 2c: Spectra integrated over given parallel momentum range<br> Intensity as a function of binding energy<br> Spectrum HeIIa h-BN Cu111 20201023 k2 042_092.txt<br> Spectrum HeIIa h-BN Cu2O Cu111 20220211 k2 041_091.txt <br> ************************* Fig. 3 2PPE spectra of Cu(111), h-BN/Cu(111) and h-BN/Cu2O/Cu(111) *************************<br> Spectra measured with SPECS Phoibos 150 WAL hemispherical analyzer (2D detector) using SpecsLab Prodigy software and<br> exported as Igor Text. All measurement parameters are given in the files. 3eV wavelength was 412nm, p-polarized.<br> A -10V bias voltage was applied to the sample.<br> Cu(111) 2PPE: P=1mW, Cu111 2022-04-14_20h47m45s.itx<br> Cu(111) 3PPE: P=3mW, Cu111 2022-04-14_21h09m29s.itx<br> h-BN/Cu(111) 2PPE: P=1.0mW, 0.5mm entrance slit, Cu111 hBN Spectrum3eV_2B_ppol.itx<br> h-BN/Cu(111) 3PPE: P=0.4mW, 3.0mm entrance slit, Cu111 hBN Spectrum3eV_4B_ppol.itx<br> h-BN/Cu2O/Cu(111) 2PPE: P~0.1mW, Cu111 hBN Cu2O 2022-02-11_17h07m34s.itx<br> h-BN/Cu2O/Cu(111) 3PPE: P~0.1mW, Cu111 hBN Cu2O 2022-02-11_16h58m49s.itx ************************************************* Fig. 4 Delay Scan *************************************************<br> Delay scans are recorded with proprietary LabView software and saved in binary HDF5 format as a 3D stack of<br> detector images (intensity as function of angular coordinate and kinetic energy) as a function of pump-probe delay.<br> Bias -5V, 3eV=413nm 0.3mW p-pol, 6eV=208nm 1nA p-pol, Ekin=11.9eV, Epass=20eV,<br> 1mm slit, exposure 10x500ms, 20 scans, 10fs steps<br> Raw data, 256 angular pixels x 348 energy pixels x 201 delays x 20 scans:<br> WAL_20220215_UZH_JB_dscan_040_0to9.h5<br> WAL_20220215_UZH_JB_dscan_040_10to19.h5<br> Sum of all scans (transposed):<br> WAL_20220215_UZH_JB_dscan_040_sum.h5<br> Cropped to active detector window and applied distortion correction and correct scaling:<br> dscan_20220215_040_data3Dcorrected.h5<br> Integrated over +-10° angular window: dscan040.itx<br> Background averaged over delay positions 0-19 subtracted and energy and delay scales corrected:<br> Fig. 4a: dscan040bgi0.itx<br> Delay scan with 50ps range and 0.2ps steps, not shown in figure but analyzed the same way: dscan041bgi.itx Fig. 4b: Intensity as a function of intermediate state energy<br> 50 fs, delay positions 40-50: dscan040t0mbg.txt<br> 1 ps, delay positions 140-150: dscan040t2mbg.txt<br> 10 ps, delay positions 55-65 in dscan041bgi: dscan041t3mbg.txt Fig. 4c: detector image obtained by averaging images at delay positions 40-50 and subtracting the background image,<br> then correcting the angular distortion by normalizing the intensity at the Fermi energy<br> dscan040image_diff0.itx <br> ************************************************* Fig. 5 Fit Curves *************************************************<br> The Igor Pro batch fitting procedure was used with a custom fitting function to fit the delay scan dscan040bgi<br> binned in 0.1 eV intervals with index 0 at -0.3 eV.<br> The displayed curves have index 13 (1.0 eV), 6 (0.3 eV) and 4 (0.1 eV). Binned delay scan: dscan040bgi_pix.itx<br> Fit parameters: dscan040bgi_fitparams.txt<br> Fit result: dscan040bgi_pixRateFits.itx<br> Fast component: dscan040bgi_FastComponent.itx<br> Slow component: dscan040bgi_SlowComponent.itx <br> ******************************************* Fig. 6 Fit Results Comparison *******************************************<br> Relaxation times are extracted from the batch fit results of different delay scans.<br> 3 nJ pump: dscan040bgi_fitparams.txt dscan_220215_040<br> 20 nJ pump: dscan010_BG4_fitparams.txt dscan220703_010<br> (data: dscan010_BG4.itx, binned: dscan010_BG4_pix.itx, fits: dscan010_BG4_pixFit.itx)<br> h-BN/Cu(111): dscan033_fitparams.txt<br> (binned data: dscan044_hBN_side_pix1.itx, fits: dscan033_hBN_side_pixFits.itx)<br> Lisowski et al.: LifetimesLisowski.txt<br> (data from M. Lisowski, P. A. Loukakos, U. Bovensiepen, and M. Wolf, Femtosecond Dynamics and Transport of Optically<br> Excited Electrons in Epitaxial Cu Films on Si(111)-7 x 7, Appl. Phys. A 79, 739 (2004))<br> Extrapolation: fit_LifetimesLisowski.txt, using power law tau=0.054797*E^(-1.1419) <br> **************************************************** Fig. S1 XPS ****************************************************<br> Preparation 1 before oxidation: Preparation 1 after oxidation: Preparation 2 after oxidation:<br> B 1s: VG2Z220209N005.pesp B 1s: VG2Z220210N023.pesp B 1s: VG2Z220628N002.pesp<br> N 1s: VG2Z220209N006.pesp N 1s: VG2Z220210N024.pesp N 1s: VG2Z220628N003.pesp<br> C 1s: VG2Z220209N007.pesp C 1s: VG2Z220210N025.pesp C 1s: VG2Z220628N004.pesp<br> O 1s: VG2Z220209N008.pesp O 1s: VG2Z220210N026.pesp O 1s: VG2Z220628N005.pesp<br> Cu 2p:VG2Z220209N009.pesp Cu 2p:VG2Z220210N027.pesp Cu 2p:VG2Z220628N006.pesp <br> **************************************************** Fig. S2 LEED ****************************************************<br> 48 eV: LEED220209_048eV_Cu111_hBN.SBIG<br> 70 eV: LEED220209_070eV_Cu111_hBN.SBIG<br> 100 eV: LEED220209_100eV_Cu111_hBN.SBIG<br> not shown in figure:<br> 40 eV: LEED220209_040eV_Cu111_hBN.SBIG<br> 120 eV: LEED220209_120eV_Cu111_hBN.SBIG <br> **************************************************** Fig. S3 LEED ****************************************************<br> 40 eV: LEED220210_040eV_Cu111_hBN_Cu2O.SBIG<br> 48 eV: LEED220210_048eV_Cu111_hBN_Cu2O.SBIG<br> 70 eV: LEED220210_070eV_Cu111_hBN_Cu2O.SBIG<br> 100 eV: LEED220210_100eV_Cu111_hBN_Cu2O.SBIG<br> 120 eV: LEED220210_120eV_Cu111_hBN_Cu2O.SBIG<br> 150 eV: LEED220210_150eV_Cu111_hBN_Cu2O.SBIG <br> **************************************************** Fig. S4 LEED ****************************************************<br> 40 eV: LEED220628_040eV_Cu111_hBN_Cu2O.SBIG<br> 48 eV: LEED220628_048eV_Cu111_hBN_Cu2O.SBIG<br> 70 eV: LEED220628_070eV_Cu111_hBN_Cu2O.SBIG<br> 100 eV: LEED220628_100eV_Cu111_hBN_Cu2O.SBIG<br> 110 eV: LEED220628_110eV_Cu111_hBN_Cu2O.SBIG<br> 140 eV: LEED220628_140eV_Cu111_hBN_Cu2O.SBIG<br> 180 eV: LEED220628_180eV_Cu111_hBN_Cu2O.SBIG<br> not shown in figure:<br> 120 eV: LEED220628_120eV_Cu111_hBN_Cu2O.SBIG<br> 150 eV: LEED220628_150eV_Cu111_hBN_Cu2O.SBIG <br> ********************************************* Fig. S5 Work function maps *********************************************<br> Ekin=10.4eV, Epass=20eV, 6eV=208.5nm 0.2nA p-pol, 1mm slit, -5V bias, exposure 1x500ms, 0.1mm steps, 81x81 pixels<br> Preparation 1:<br> Data cube after lens correction and correct scaling: dscan_220221_003_data3Dcorrected.h5<br> Integrated over all angles and brought into raster format: dscan_220221_003_raster.h5<br> Work function map: dscan_220221_003_rasterWF.itx<br> Inset: Photograph of the sample after preparation 1, "Photograph hBN Cu2O Cu.png"<br> Preparation 2:<br> Data cube after lens correction and correct scaling: dscan_220704_011_data3Dcorrected.h5<br> Integrated over all angles: dscan_220704_011_raster.h5<br> Work function map: dscan_220704_011_rasterWF.itx <br> ************************************************ Fig. S6 Delay Scans ************************************************<br> See description of Fig. 4 for processing details. Pump power was measured with a thermal powermeter and probe power<br> was measured with a Thorlabs SM05PD7A GaP-photodiode with 14.4 mA/W sensitivity at 208nm.<br> The thermal powermeter has an accuracy of +-0.1mW.<br> 1.0mW pump power at 100kHz repetition rate equals 10nJ pulse energy.<br> 1.0nA photodiode current equals approximately 70nW probe power or 0.7 pJ probe energy. Common settings: Bias voltage -5V, exposure time 20x500ms, 20 scans, 20fs steps, entrance slit size 1mm,<br> Pass energy 20eV, Kinetic energy 11.9 eV, pump wavelength 413nm, pump and probe beam are p-polarized.<br> Differing settings are written for each dataset. Fig. S6a: dscan_220215_040/dscan040bgi0.itx, processed raw data: dscan_220215_040_data3Dcorrected.h5<br> 0.3mW pump, 208nm 1.0nA probe, 10fs steps, exposure 10x500ms<br> Fig. S6b: dscan_220217_045/dscan045bgi.itx, processed raw data: dscan_220217_045_data3Dcorrected.h5<br> 0.3mW pump, 208nm 1.0nA probe, 10fs steps, Ekin=13.3eV, Epass=30eV, 7mm slit, 50 scans<br> Fig. S6c: dscan_220216_041/dscan041bgi.itx, processed raw data: dscan_220216_041_data3Dcorrected.h5<br> 0.3mW pump, 208nm 1.0nA probe, 200fs steps, exposure 10x500ms, 10 scans <br> ************************************************ Fig. S7 Delay Scans ************************************************<br> Common settings: same as in Fig. S6 Fig. S7a: dscan_220701_020/dscan020bgi0.itx, processed raw data: dscan_220701_020_data3Dcorrected.h5<br> 0.5mW pump, 209nm 0.9nA probe, 3mm slit<br> Fig. S7b: dscan_220712_029/dscan029_BG.itx, processed raw data: dscan_220712_029_data3Dcorrected.h5<br> 1.5mW pump, 209nm 1.0nA probe<br> Fig. S7c: dscan_220703_010/dscan010_BG4.itx, processed raw data: dscan_220703_010_data3Dcorrected.h5<br> 2.0mW pump, 209nm 0.9nA probe<br> Fig. S7d: dscan_220417_033/dscan033_hBN_side0.itx, processed raw data: dscan_220417_033_data3Dcorrected.h5<br> 1.0mW pump, 208nm 0.1nA probe, Ekin=11.8eV, 40 scans <br> *********************************************** Fig. S8 Beam profiles ***********************************************<br> 8-bit CCD images were acquired with a Basler puA1280-54um CCD camera and Basler pylonViewer 5.0 acquisition software.<br> Sensor resolution: 1280x960, pixel size: 3.75x3.75 micrometers<br> 3 eV image: 10 microseconds exposure time, Spot3eV 10us 20mm.bmp<br> 6 eV image: 100 milliseconds exposure time, Spot6eV 100ms 20mm.bmp
description: Additional funding from University of Zurich through UZH Candoc Grant FK-21-082.