P66 Time-resolved Luminescence Spectroscopy

PETRA III at DESY

The P66 beamline offers a variety of time- resolved and steady state VIS- UV- VUV luminescence spectroscopy methods. Thermo-, photo- stimulated luminescence spectroscopy, optical absorption and polarized reflectivity methods are avaliable as well.

The P66 optical beam source is a 2.1 meter long bending magnet providing 10¹³ photons in a VUV energy range. Two gold coated optical mirrors focus the beam in Horizontal (M1) and vertical (M2) planes on a entrance slit of the primary monochromator. The McPherson primary monochromator is 2-meter normal incidence type monochromator provide phootons in a energy range 4 eV to 40 eV.

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Beamline Energy Resolution

0.8 * 10^-4 [meV] @ 10 [eV]

Beamline Energy Range

4 - 40 [eV]

Max Flux On Sample

4.5 * 10¹³ [ph/s] @ 10 [eV]

Spot Size On Sample Hor

0.5 - 4 [mm]

Spot Size On Sample Vert

0.03 - 0.1 [mm]

Divergence Hor

2.1 [mrad]

Divergence Vert

12 [mrad]

Angle Of Incidence Light On Sample Value

17 - 90 [degrees]

Photon Sources

Bending Magnet

Type

Bending Magnet

Available Polarization

Linear horizontal

Source Divergence Sigma

X = 12 [urad], Y = 2.2 [urad]

Source Size Sigma

X = 140 [um], Y = 20 [um]

Source Spectral Flux

4.5 * 10¹³ [ph/s/0.1%bw] @ 10 [eV]

Monochromators

2-m normal incidence McPherson monochromator

Energy Range

4 - 40 [eV]

Type

2- meter normal incidence monochromator in 15 degree mounting is equipped with two holographic concave gratings (1200 grooves/mm, Al-MgF2 coating)

Number Of Gratings

Grating Type

Al optical grating - 1200 l/mm for 65- 330 nm region, with 0.02 nm best resolution
Pt optical grating - 1200 l/mm for 30- 330 nm region, with 0.02 nm best resolution

Pre-focusing Mirror Type

M1 - gold coated plane cylindrical mirror, focus in horizontal plane on the entrance slit of McPherson monochromator
M2 - gold coated plane elliptical mirror, focus in vertical plane on the entrance slit of McPherson monochromator

Refocusing Mirror Type

M3- gold coated toroidal mirror, focus on the sample

Other Optics

M1 plane cylindrical Mirror

Description

Substrate material: Si
Substrate dimension (L x W x H): 100mm x 160mm x 40mm
Surface geometry: Plane cylinder
Clear aperture size: 90 mm x 150 mm
Geometry parameters (radius): R = 2996 mm ± 15 mm
Microroughness: 0.3 nm
Coating: Au 50 nm

M2 plane elliptical mirror

Description

Substrate material: fused silica
Substrate dimension (L x W x H): 200mm x 60mm x 30mm
Surface geometry: plane ellipse
Clear aperture size: 180 mm x 50 mm
Geometry parameters:
Semi-major axis: 11300 mm
Semi-minor axis: 1311.5 mm
Semi-focal-length: 11224 mm
Eccentricity: 0.9932
Microroughness: 0.3nm
Coating: Au 50nm

M3 toroidal mirror

Description

Substrate material: Fused Silica
Substrate dimension (L x W x H): 80mm x 40mm x 45mm
Surface geometry: toroidal mirror
Clear aperture size: 70 mm x 30 mm
Geometry parameters:
R1=1950mm
R2=112mm
Microroughness: 0.3nm
Coating: Au 50nm

Endstations or Setup

P66 endstation

Description

The endstation of the P66 beamline is consist from: VUV sample chamber, manipulated cryostat with sample holder and two secondary monochromators for luminescence analysis.

Spectrometer

VUV 0.4 m Pouyet type spectrometer (spectral range 100- 300 nm)
VIS Andor kymera 328i-B1 monochromator (spectral range 200- 1100 nm)

Base Pressure

1 * 10⁹ [mbar]

Sample

Sample Type

Crystal

Other Sample Type

Powder, Thin film

Mounting Type

Samples are glued on sample holder with silver paste for better heat conductivity

Required Sample Size

X = 7 [mm], Y = 5 [mm], Z = 2 [mm]

Techniques usage

Absorption / Time-resolved studies

For the measurements of time-resolved spectra or decay kinetics, the data collected using a single photon counting method. A single photon causes a signal pulse from the detector and afterwards each pulse is processed separately.

Emission or Reflection / Polarimetry

No principal difference exists for luminescence emission and excitation measurements. Only, the monochromator to be scanned is different. The photon energy of excitation is selected for luminescence measurements and the luminescence intensity is measured as a function of emitted photon energy. On the contrary, the photon energy of luminescence is fixed for the excitation spectra. The intensity of respective luminescence is measured as a function of photon energy of excitation.

Emission or Reflection / Reflectrometry

For reflection measurements, the sample is adjusted in a way that the specular reflection from the sample surface is directed to the sodium salicylate coated window. The sodium salycilate luminescence, excited by reflected light is measured instead of of the direct VUV reflection.

Manipulator or Sample stage

Description

The KONTI cryostat for UHV Physics from CryoVac company mounted on X/Y/Z/ Rotation 360° manipulator for manual manipulation.

Degrees Of Freedom

Positioning Precision

X = 0.5 [mm], Y = 0.5 [mm], Z = 0.5 [mm]

Range Of Movement

X = 17 [mm], Y = 17 [mm], Z = 50 [mm]

Sample Environment

Description

P66 beamline operates in UHV conditions. The pressure 1 x 10e8 mbar or lower is required to start the operation.

Pressure (min)

1 * 10¹⁰ [mbar]

Pressure (Max)

1 * 10⁸ [mbar]

Temperature

4.2 - 700 [K]

Sample Holders

Type

Double sided copper plate with 3 holes for optical absorption measurements.

Description

The sample holder is made from oxygen free copper and mounted on liquid Helium continuous flow KONTI cryostat. The dimension of the sample holder is 80 x 26 mm.

Degrees Of Freedom

contacts

Aleksei Kotlov

Techniques

Absorption

Time-resolved studies

Emission or Reflection

Polarimetry
Reflectrometry
Time-resolved studies

Disciplines

Chemistry

Other - Chemistry

Engineering & Technology

Detectors
Technique Development - Engineering & Technology

Material Sciences

Other - Material Sciences

Physics

Optics
Surfaces, interfaces and thin films

Address

Notkestrasse 85, Geb. 47K

control/Data analysis

Control Software Type

LINUX and WINDOWS based various software

Data Output Type

ASCII

Data Output Format

ASCII

Softwares For Data Analysis

SOLIS, ORIGIN

Equipment That Can Be Brought By The User

Tunable pulsed laser for Pump- Probe experiments